JSON canvas initial

Makefile

@@ -4,10 +4,6 @@ COMPANION_WIN := companion/datascape-companion-windows-amd64.exe
 COMPANION_LIN := companion/datascape-companion-linux-amd64
 COMPANION_SRCS := $(wildcard cmd/companion/*.go) $(wildcard cmd/companion/*.html) go.mod go.sum
 
-# Release builds drop the symbol table, DWARF debug info and local source
-# paths. Panics still print file:line stack traces; only debuggers lose out.
-RELEASE_FLAGS := -trimpath -ldflags="-s -w"
-
 EDITOR_BUNDLE := assets/editor/vendor/codemirror.bundle.js
 EDITOR_SRCS := $(wildcard editor-build/*.js) editor-build/package.json editor-build/package-lock.json
 
@@ -18,10 +14,10 @@ EDITOR_SRCS := $(wildcard editor-build/*.js) editor-build/package.json editor-bu
 companion-release: $(COMPANION_WIN) $(COMPANION_LIN)
 
 $(COMPANION_WIN): $(COMPANION_SRCS)
-	GOOS=windows GOARCH=amd64 go build -trimpath -ldflags="-s -w -H windowsgui" -o $@ ./cmd/companion
+	GOOS=windows GOARCH=amd64 go build -ldflags="-H windowsgui" -o $@ ./cmd/companion
 
 $(COMPANION_LIN): $(COMPANION_SRCS)
-	GOOS=linux GOARCH=amd64 go build $(RELEASE_FLAGS) -o $@ ./cmd/companion
+	GOOS=linux GOARCH=amd64 go build -o $@ ./cmd/companion
 
 companion-windows: $(COMPANION_WIN)
 companion-linux: $(COMPANION_LIN)
@@ -41,7 +37,7 @@ $(EDITOR_BUNDLE): $(EDITOR_SRCS)
 	cd editor-build && npm ci && npm run build
 
 deploy: companion-release
-	GOOS=linux GOARCH=arm GOARM=7 go build $(RELEASE_FLAGS) -o datascape-arm .
+	GOOS=linux GOARCH=arm GOARM=7 go build -o datascape-arm .
 	ssh $(NAS) 'kill $$(cat /share/homes/luxick/.local/bin/datascape.pid) 2>/dev/null; rm -f /share/homes/luxick/.local/bin/datascape.pid'
 	scp datascape-arm $(NAS):/share/homes/luxick/.local/bin/datascape
 	ssh $(NAS) /share/homes/luxick/.local/bin/datascape-start.sh

README.md

@@ -4,126 +4,190 @@ Minimal self-hosted personal wiki. Folders are pages.
 
 ## Features
 
-- **Pages**: a folder's `index.md` renders as HTML, and the folder's other files are listed below it. Going to a missing path lets you create the page there.
+- **Pages** every folder is a page. Place an `index.md` inside a folder and it renders as HTML. Drop any other files (PDFs, images, etc.) alongside it and they appear in the listing below the content. Navigating to a path that does not exist shows a **[CREATE]** prompt.
-- **Editing**: edit the whole page or a single heading's section. Tick task checkboxes directly on the rendered page.
-- **Move, rename, delete**: moving a page onto an empty folder offers to merge into it.
-- **View settings**: show the file list as a list or thumbnail grid, sorted by name, date, or size. Videos get thumbnails when `ffmpeg` is installed.
-- **Search**: find pages by name.
-- **Wikilinks**: `[[query]]` or `[[query::label]]`. They open a search, so links still work after a page is renamed. Typing `[[` in the editor suggests page names. Embed files with `![caption](photo.jpg "left")`.
-- **Movie import**: create a page from OMDb metadata. Asks once for a free [OMDb API key](https://www.omdbapi.com/apikey.aspx) and keeps it in the browser.
-- **Special folders**: a [photo diary](#diary) and a [fitness dashboard](#fitness).
-- **Calendars**: Nextcloud calendars mirrored into the wiki. They add events and weight to the diary, and a [maintenance widget](#calendars) to every page.
-- **Quick-add bookmarklet**: save the current tab to a wiki page.
-- **Companion app**: an optional desktop helper, downloadable from the wiki footer. It opens wiki files in local apps and folders in the file manager.
 
-## Build & run
+- **View settings** per folder, display the file listing as a list or thumbnail grid and pick the sort key/order, via the **view** button in the `Files` header. See the [View Settings](#view-settings) section.
 
-The wiki binary embeds the companion binaries, so build those first:
+- **Search** search across all page names (folder names) in the wiki, accessible from the navigation bar.
+
+- **Wikilinks** link between pages with `[[search query]]` syntax, or `[[query::display text]]` to override the label. The link opens the search page for that query, so it keeps resolving after a page is renamed or moved. Files embed with standard Markdown image syntax — `![caption](photo.jpg "left")` — relative to the page they sit on.
+
+- **Canvases** an infinite pan/zoom board stored as a [JSON Canvas](https://jsoncanvas.org/) `.canvas` file next to the page's `index.md`. Canvases in a folder appear as tabs above the page content, so a canvas is an alternative *view* of the page rather than a separate document. See the [Canvases](#canvases) section.
+
+- **Movie import** import movie entries via the OMDb API. Fetches title, year, runtime, genre, director, cast, plot, and poster, and pre-fills a new page with that metadata.
+
+- **Special folder types** folders can opt into custom rendering (e.g. a photo diary with calendar navigation). See the [Special Folder Types](#special-folder-types) section for details.
+
+- **Quick-add bookmarklet** save the current browser tab to a predetermined wiki page (e.g. `/Topics/Bookmarks/`) with one click. See the [Quick-Add Bookmarklet](#quick-add-bookmarklet) section.
+
+## Build
 
 ```bash
-make companion-release                         # once, and after companion changes
+# local
-go build -o datascape .                        # local
+go build -o datascape .
-make deploy                                    # QNAP NAS: stripped ARMv7 build, copy, restart
+
-./datascape -dir ./wiki -addr :8080 -user me -pass secret
+# QNAP NAS (linux/arm)
+GOOS=linux GOARCH=arm go build -o datascape .
 ```
 
-| Flag | Default | |
+## Usage
-|------|---------|-|
+
+```bash
+go run . -dir ./wiki -addr :8080
+go run . -dir ./wiki -addr :8080 -user me -pass secret
+```
+
+| Flag | Default | Description |
+|------|---------|-------------|
 | `-addr` | `:8080` | Listen address |
-| `-dir` | `./wiki` | Wiki root |
+| `-dir` | `./wiki` | Wiki root directory |
-| `-cache` | `./cache` | Thumbnail cache |
+| `-cache` | `./cache` | Thumbnail cache directory |
-| `-user`, `-pass` | | Basic auth (omit to disable) |
+| `-user` | _(none)_ | Basic auth username — omit to disable auth |
-| `-reindex-interval` | `30m` | Search index rebuild (`0` = off) |
+| `-pass` | _(none)_ | Basic auth password |
-| `-calendars` | `Calendars` | [Calendars](#calendars) folder, relative to `-dir` (empty = off) |
+| `-reindex-interval` | `30m` | Periodic search index rebuild interval (`0` disables) |
-| `-tz` | system | Time zone for calendars and the diary, e.g. `Europe/Berlin` |
 
-## `.page-settings`
+## View Settings
 
-Per-folder `key = value` file. The **view** button in the `Files` header sets the first three keys.
+The **view** button in a folder's `Files` header sets how its listing renders,
+persisting three keys to `.page-settings`:
 
 | Key | Values (default first) |
-|-----|------------------------|
+|------|------------------------|
 | `view` | `list`, `thumbnail` |
-| `sort` | `name`, `modified`, `size` |
+| `sort` | `name`, `modified`, `size` (folders always sort by name, grouped first) |
 | `order` | `asc`, `desc` |
-| `type` | `diary`, `fitness`, `calendars` |
 
-## Keyboard shortcuts
+## Special Folder Types
 
-All use Alt+Shift.
+A folder can opt into special rendering by adding a `.page-settings` file. The
-
+same file also holds the [View Settings](#view-settings) keys; only the `type`
-| Where | Keys |
+key selects a special renderer:
-|-------|------|
-| Anywhere | `E` edit, `N` new page, `M` move, `F` search, `H` maintenance |
-| Editor | `S` save, `1`–`3` heading, `B`/`I` bold/italic, `C`/`K` code/code block, `L` link, `P` wikilink, `G` embed, `U`/`O`/`X` bullet/numbered/task list, `Q` quote, `R` rule, `T` format table, `D`/`W` date (ISO/long), `V` movie, `Y` delete line |
-
-## Diary
 
 ```
-Diary/
+type = diary
-  .page-settings         ← type = diary
-  2026/
-    index.md             ← # 2026, ## 2026-05, ### 2026-05-11 sections
-    2026-05-11 Beach.jpg ← photos go under their date's section
 ```
 
-The year page shows each day's section with its photos. Months and days that are missing (up to today) appear as placeholders with an `[edit]` button. A calendar in the sidebar jumps to any date.
+### Diary
 
-Bookmarkable shortcuts: `<diary>/today/`, `<diary>/this-month/`, `<diary>/this-year/`.
+Designed for a chronological photo diary. The whole year lives in a single
-
+file as ISO-headed sections; photos are loose JPEGs named with a date prefix.
-## Fitness
-
-With `type = fitness`, a folder shows weight charts (daily and weekly mean) below its content. The weights come from the calendars with the `weight` role (see [Calendars](#calendars)). Add `weight-goal = 85` to the folder's `.page-settings` to draw a goal line.
-
-## Calendars
 
 ```
-Calendars/
+FolderName/
-  .page-settings   ← type = calendars, roles, sync credentials
+  .page-settings        ← type = diary
-  Personal.ics     ← one file per calendar
+  YYYY/
-  Gewicht.ics
+    index.md            ← `# YYYY` + `## YYYY-MM` + `### YYYY-MM-DD` sections
-  …
+    YYYY-MM-DD Desc.jpg ← photos named with the date they belong to
 ```
 
-Pages only read these local files and never contact the calendar server. The built-in sync downloads all calendars of a CalDAV calendar home in the background. Or you can put the `.ics` files there yourself.
+The year page (`YYYY/`) renders every section in the file with photos
+attached to each `### YYYY-MM-DD` heading. Months and days the file doesn't
+yet contain are rendered as **virtual** headings with an `[edit]` button that
+splices a new section into the year file at the right chronological position;
+virtual day headings still carry photos for that date. Past years render
+every month/day slot; the current year stops at today; future years skip
+virtual entries entirely. The file may contain non-date headings (e.g.
+`## Events` → `### Festival` between `# YYYY` and `## YYYY-01`); these keep
+their document position.
 
-```
+A sidebar calendar widget shows one month grid at a time; the month-name
-type = calendars
+button opens a dropdown of all twelve months, and a separate year dropdown
+jumps between years. Day cells link to the matching anchor on the year page
+regardless of whether the date has a real section yet.
 
-# Roles: file names without .ics
+#### Persistent date links
-diary = Personal, Feiertage
-weight = Gewicht
-maintenance = Maintainance
 
-# Sync (Nextcloud)
+Each diary root exposes three stable paths intended for browser bookmarks.
-caldav-url = https://cloud.example/remote.php/dav/calendars/me/
+They resolve against the year page rather than separate per-day URLs:
-caldav-user = me
-caldav-pass = xxxxx-xxxxx-xxxxx-xxxxx-xxxxx
-sync-interval = 15m
-```
 
-| Key | |
+| Path | Redirects to |
-|-----|-|
+|------|-------------|
-| `diary` | Events shown under each diary day: all-day first, then by start time |
+| `<diary>/today/` | `<diary>/YYYY/#YYYY-MM-DD` (or the year file's insert-section editor when today's section doesn't exist yet) |
-| `weight` | Titles like `95,6kg`, shown under the diary day's events |
+| `<diary>/this-month/` | `<diary>/YYYY/#YYYY-MM` |
-| `maintenance` | Tasks in the header widget (with the number due today) and on the calendars page |
+| `<diary>/this-year/` | `<diary>/YYYY/` |
-| `caldav-url` | Calendar home. Empty = no sync |
-| `caldav-user`, `caldav-pass` | Use a Nextcloud app password (Settings → Security), not the account password |
-| `sync-interval` | Default `15m`. `0` = only at startup and with **Sync now** |
 
-Changes apply without a restart. Each calendar is saved as `<display name>.ics`. A download that fails or is not valid iCalendar keeps the old file. Datascape never serves dotfiles, so the password in `.page-settings` cannot be downloaded. It is still in every backup of the wiki folder.
+Legacy `YYYY/MM/` and `YYYY/MM/DD/` URLs (no longer the canonical form) redirect to the matching anchor on the year page.
 
-The calendars page lists the maintenance tasks (repeat rule, last date, next date) and the sync status of each calendar.
+## Canvases
 
-## Quick-add bookmarklet
+A canvas is a `<Name>.canvas` file in a page folder holding a
+[JSON Canvas 1.0](https://jsoncanvas.org/spec/1.0/) document. Every canvas in a
+folder renders as a tab above that page's content, and the page itself is the
+first tab — so a page and its diagrams are one thing with several views.
 
-Replace `wiki.host` and `/Topics/Bookmarks/` with your host and target page:
+| URL | What it does |
+|------|-------------|
+| `<page>/?canvas=<Name>` | the canvas view (canonical) |
+| `<page>/<Name>.canvas` | redirects to the canonical form |
+| `<page>/<Name>.canvas?raw` | the file itself |
+
+Create one from the **NEW CANVAS** action or the `+` in the tab strip.
+
+### Nodes
+
+All four spec node types render:
+
+| Type | Rendered as |
+|------|-------------|
+| `text` | markdown, rendered server-side — wikilinks, `![[embeds]]`, tables and task lists all behave as they do on a page |
+| `file` | a transclusion of another wiki path: markdown pages (narrowed to a heading when `subpath` is set), images, video, PDFs |
+| `link` | a card for an external URL |
+| `group` | a labelled frame; dragging it carries the nodes inside it |
+
+Node content is rendered by the server and cached in the browser by *content*,
+so the whole canvas arrives pre-rendered in the initial page load (no per-node
+requests) and undo/redo of a text edit costs nothing.
+
+### Controls
+
+| Gesture | Action |
+|---------|--------|
+| drag background | pan |
+| ctrl/⌘ + wheel, or pinch | zoom |
+| shift + drag background | marquee select |
+| drag a node | move it (snaps to a 20px grid; hold alt to bypass) |
+| drag a corner handle | resize |
+| drag a side port | draw an edge to another node |
+| double-click a node | edit it |
+| double-click empty space | new text node there |
+
+Keys: `Ctrl+S` save · `Ctrl+Z` / `Ctrl+Shift+Z` undo/redo · `Del` delete
+selection · `Ctrl+A` select all · arrows nudge (shift for single pixels) ·
+`T`/`F`/`L`/`G` add a node · `+`/`-`/`0` zoom, `9` fit · `Esc` cancel.
+
+Undo covers the whole session; a drag or resize is one entry no matter how many
+events it spanned.
+
+### Saving
+
+Saving is explicit (**SAVE**, or `Ctrl+S`) and uploads the whole document. The
+server parses and validates it before writing anything, so a malformed payload
+can never land on disk, and four things are checked in order:
+
+1. the JSON parses into the spec's shape;
+2. node ids are unique, every edge endpoint resolves, and enums/colours/sizes are in range;
+3. the `X-Canvas-Version` token matches the file on disk — a mismatch is a `409` and you are asked whether to reload or overwrite;
+4. a save that would empty a populated canvas is refused until you confirm it.
+
+The previous contents are kept beside the file as `.<Name>.canvas.bak`, and the
+write itself is atomic. Leaving the page with unsaved changes prompts first.
+
+`[[wikilinks]]` inside text nodes are search queries, like on a page, so they
+keep resolving after a move. File nodes and group backgrounds hold literal
+paths and are not rewritten: moving or renaming their target leaves them
+rendered as broken references.
+
+Canvas *contents* are not searchable; only the file name is indexed.
+
+## Quick-Add Bookmarklet
+
+Replace `wiki.host` with your wiki host and `/Topics/Bookmarks/` with the destination page (one bookmarklet per target):
 
 ```javascript
 javascript:(function(){var s=window.getSelection().toString().trim();var t=s||document.title;var u=location.href;var to='/Topics/Bookmarks/';var q='?to='+encodeURIComponent(to)+'&url='+encodeURIComponent(u)+'&title='+encodeURIComponent(t);window.open('https://wiki.host/quickadd'+q,'quickadd','width=480,height=320');})();
 ```
 
-Each save adds this to the target page's `index.md`:
+Each save appends an entry of the following form to the destination page's `index.md`:
 
 ```markdown
 - [Example Page](https://example.com)

assets/calendar/page.html

@@ -1,45 +0,0 @@
-<h2 id="maintenance">Maintenance</h2>
-{{if .Maintenance}}
-<div class="cal-scroll"><table class="data-table panel cal-table">
-    <thead><tr><th>Task</th><th>Repeats</th><th>Last</th><th>Next</th></tr></thead>
-    <tbody>
-    {{range .Maintenance}}
-    <tr><td>{{.Summary}}</td><td class="muted">{{.Rule}}</td><td class="nowrap">{{.Last}}</td><td class="nowrap">{{.Next}}</td></tr>
-    {{end}}
-    </tbody>
-</table></div>
-{{else if .HasMaintenance}}
-<p class="muted">No maintenance tasks within a year of today.</p>
-{{else}}
-<p class="muted">No maintenance calendar. Set <code>maintenance = &lt;name&gt;</code> in this folder's <code>.page-settings</code>.</p>
-{{end}}
-
-<h2 id="calendars">Calendars</h2>
-{{if .Calendars}}
-<div class="cal-scroll"><table class="data-table panel cal-table">
-    <thead><tr><th>Calendar</th><th>Role</th><th>Events</th><th>Updated</th></tr></thead>
-    <tbody>
-    {{range .Calendars}}
-    <tr>
-        <td>{{.Name}}{{if .Error}}<div class="cal-error">{{.Error}}</div>{{end}}</td>
-        <td class="muted">{{.Roles}}</td>
-        <td>{{.Events}}</td>
-        <td class="nowrap">{{.Updated}}</td>
-    </tr>
-    {{end}}
-    </tbody>
-</table></div>
-{{else}}
-<p class="muted">No <code>.ics</code> files in this folder yet.</p>
-{{end}}
-{{if .IsSyncDir}}
-{{if .SyncEnabled}}
-<form class="cal-sync row" method="post" action="?calsync">
-    <button type="submit" class="btn">Sync now</button>
-    <span class="muted">{{if .LastRun}}Last sync: {{.LastRun}}{{else}}Not synced yet{{end}}</span>
-</form>
-{{if .LastError}}<p class="cal-error">{{.LastError}}</p>{{end}}
-{{else}}
-<p class="muted">Sync is off. Set <code>caldav-url</code>, <code>caldav-user</code> and <code>caldav-pass</code> in this folder's <code>.page-settings</code>.</p>
-{{end}}
-{{end}}

assets/calendar/widget.html

@@ -1,16 +0,0 @@
-<span class="dropdown maint">
-    <button type="button" class="btn maint-toggle{{if not .Count}} is-idle{{end}}" data-action="maint-menu" aria-haspopup="true" aria-expanded="false" title="Maintenance (H)">{{icon "maintenance"}}<span class="maint-count">{{.Count}}</span></button>
-    <div class="dropdown-menu align-right maint-menu">
-        <div class="panel-header">Today</div>
-        <div class="maint-list">
-            {{range .Today}}<span class="maint-when">{{.When}}</span><span>{{.Summary}}</span>
-            {{else}}<span class="muted">Nothing due</span>{{end}}
-        </div>
-        <div class="panel-header">Next 7 days</div>
-        <div class="maint-list">
-            {{range .Upcoming}}<span class="maint-when">{{.When}}</span><span>{{.Summary}}</span>
-            {{else}}<span class="muted">Nothing planned</span>{{end}}
-        </div>
-        {{if .PageURL}}<a class="btn btn-block maint-all" href="{{.PageURL}}">All maintenance →</a>{{end}}
-    </div>
-</span>

assets/canvas/doc.js

@@ -0,0 +1,182 @@
+// doc.js — the canvas document plus its undo stack.
+//
+// Every mutation passes through begin()/commit(). A gesture (a drag, a resize,
+// a nudge-repeat) spans hundreds of pointer events but has to collapse into a
+// single undo entry, so the snapshot is taken once at begin() and pushed once
+// at commit() — and only when the document actually changed, so a click that
+// moves nothing leaves no trace.
+//
+// Undo is snapshot-based rather than a stack of inverse operations: the
+// document is a small pure-JSON object, cloning it costs microseconds, and a
+// snapshot cannot be subtly wrong the way a hand-written inverse can. The
+// stack is capped so a long session cannot grow without bound.
+window.Canvas = window.Canvas || {};
+
+Canvas.Doc = (function () {
+    var MAX_UNDO = 100;
+
+    var doc = { nodes: [], edges: [] };
+    var undoStack = [];
+    var redoStack = [];
+    var pending = null;
+    var dirty = false;
+    var version = '';
+    var listeners = [];
+
+    function clone(v) { return JSON.parse(JSON.stringify(v)); }
+
+    function emit() {
+        for (var i = 0; i < listeners.length; i++) listeners[i]();
+    }
+
+    // newId mints a 16-hex-character node/edge id, the shape the format uses in
+    // the wild. Collisions are checked against the live document anyway.
+    function newId() {
+        var bytes = new Uint8Array(8);
+        window.crypto.getRandomValues(bytes);
+        var out = '';
+        for (var i = 0; i < bytes.length; i++) {
+            out += (bytes[i] + 0x100).toString(16).slice(1);
+        }
+        if (find(doc.nodes, out) || find(doc.edges, out)) return newId();
+        return out;
+    }
+
+    function find(list, id) {
+        for (var i = 0; i < list.length; i++) {
+            if (list[i].id === id) return list[i];
+        }
+        return null;
+    }
+
+    return {
+        init: function (d, hash) {
+            doc = (d && typeof d === 'object') ? d : {};
+            if (!Array.isArray(doc.nodes)) doc.nodes = [];
+            if (!Array.isArray(doc.edges)) doc.edges = [];
+            undoStack = [];
+            redoStack = [];
+            pending = null;
+            dirty = false;
+            version = hash || '';
+        },
+
+        get: function () { return doc; },
+        nodes: function () { return doc.nodes; },
+        edges: function () { return doc.edges; },
+        node: function (id) { return find(doc.nodes, id); },
+        edge: function (id) { return find(doc.edges, id); },
+        newId: newId,
+
+        // edgesFor returns every edge touching any of the given node ids.
+        edgesFor: function (nodeIds) {
+            var want = {};
+            nodeIds.forEach(function (id) { want[id] = true; });
+            return doc.edges.filter(function (e) {
+                return want[e.fromNode] || want[e.toNode];
+            });
+        },
+
+        // --- gesture bracketing ---
+        //
+        // Nested begin() calls join the outer gesture rather than starting a
+        // new one, so a composite action (drag a group, which drags its
+        // members) still produces exactly one undo entry.
+        begin: function (label) {
+            if (pending) { pending.depth++; return; }
+            pending = { label: label || '', before: clone(doc), depth: 0 };
+        },
+
+        commit: function () {
+            if (!pending) return;
+            if (pending.depth > 0) { pending.depth--; return; }
+            var before = pending.before;
+            var label = pending.label;
+            pending = null;
+            // A gesture that changed nothing (a click that selected without
+            // moving) must not push an undo entry the user would have to press
+            // Ctrl+Z through.
+            if (JSON.stringify(before) === JSON.stringify(doc)) return;
+            undoStack.push({ label: label, doc: before });
+            if (undoStack.length > MAX_UNDO) undoStack.shift();
+            redoStack.length = 0;
+            dirty = true;
+            emit();
+        },
+
+        // abort rolls the document back to the gesture's starting state, for
+        // Escape mid-drag.
+        abort: function () {
+            if (!pending) return;
+            if (pending.depth > 0) { pending.depth--; return; }
+            doc = pending.before;
+            pending = null;
+            emit();
+        },
+
+        inGesture: function () { return pending !== null; },
+
+        undo: function () {
+            if (!undoStack.length) return false;
+            var entry = undoStack.pop();
+            redoStack.push({ label: entry.label, doc: clone(doc) });
+            doc = entry.doc;
+            dirty = true;
+            emit();
+            return true;
+        },
+
+        redo: function () {
+            if (!redoStack.length) return false;
+            var entry = redoStack.pop();
+            undoStack.push({ label: entry.label, doc: clone(doc) });
+            doc = entry.doc;
+            dirty = true;
+            emit();
+            return true;
+        },
+
+        canUndo: function () { return undoStack.length > 0; },
+        canRedo: function () { return redoStack.length > 0; },
+
+        // --- structural helpers ---
+
+        addNode: function (node) {
+            doc.nodes.push(node);
+            return node;
+        },
+
+        addEdge: function (edge) {
+            doc.edges.push(edge);
+            return edge;
+        },
+
+        // remove drops the named nodes and edges. Every edge touching a removed
+        // node goes too — a dangling endpoint would fail validation on save, so
+        // it can never be allowed to exist even transiently.
+        remove: function (nodeIds, edgeIds) {
+            var deadNodes = {};
+            (nodeIds || []).forEach(function (id) { deadNodes[id] = true; });
+            var deadEdges = {};
+            (edgeIds || []).forEach(function (id) { deadEdges[id] = true; });
+
+            doc.nodes = doc.nodes.filter(function (n) { return !deadNodes[n.id]; });
+            doc.edges = doc.edges.filter(function (e) {
+                return !deadEdges[e.id] && !deadNodes[e.fromNode] && !deadNodes[e.toNode];
+            });
+        },
+
+        // --- save state ---
+
+        isDirty: function () { return dirty; },
+        markSaved: function (hash) {
+            dirty = false;
+            if (hash) version = hash;
+            emit();
+        },
+        version: function () { return version; },
+
+        onChange: function (fn) { listeners.push(fn); },
+        notify: emit
+    };
+})();

assets/canvas/edges.js

@@ -0,0 +1,237 @@
+// edges.js — the SVG edge layer.
+//
+// Edges are cubic beziers anchored at the midpoint of a node side, with control
+// points pushed out along that side's normal. When a side is unspecified the
+// dominant axis between the two centres picks one, which keeps auto-routed
+// edges predictable instead of hunting for a global minimum.
+//
+// The SVG sits inside the transformed world and draws in world coordinates, so
+// it pans and zooms with the nodes for free.
+window.Canvas = window.Canvas || {};
+
+Canvas.Edges = (function () {
+    var Doc = Canvas.Doc;
+    var Select = Canvas.Select;
+
+    var SVGNS = 'http://www.w3.org/2000/svg';
+    var ARROW = 11;
+
+    var svg = null;
+    var groups = {};   // edge id -> <g>
+    var temp = null;   // the rubber-band path while drawing a new edge
+
+    function el(name, attrs) {
+        var node = document.createElementNS(SVGNS, name);
+        for (var k in attrs) {
+            if (Object.prototype.hasOwnProperty.call(attrs, k)) node.setAttribute(k, attrs[k]);
+        }
+        return node;
+    }
+
+    // sideAnchor returns the connection point on a node side together with that
+    // side's outward normal, which the control points and arrowheads both need.
+    function sideAnchor(n, side) {
+        switch (side) {
+            case 'top': return { x: n.x + n.width / 2, y: n.y, nx: 0, ny: -1 };
+            case 'bottom': return { x: n.x + n.width / 2, y: n.y + n.height, nx: 0, ny: 1 };
+            case 'left': return { x: n.x, y: n.y + n.height / 2, nx: -1, ny: 0 };
+            default: return { x: n.x + n.width, y: n.y + n.height / 2, nx: 1, ny: 0 };
+        }
+    }
+
+    // autoSides picks the facing sides for an edge with no explicit ones: the
+    // dominant axis between the node centres wins. Simple and stable — the edge
+    // does not flip sides every time a node moves a few pixels.
+    function autoSides(a, b) {
+        var dx = (b.x + b.width / 2) - (a.x + a.width / 2);
+        var dy = (b.y + b.height / 2) - (a.y + a.height / 2);
+        if (Math.abs(dx) >= Math.abs(dy)) {
+            return dx >= 0 ? ['right', 'left'] : ['left', 'right'];
+        }
+        return dy >= 0 ? ['bottom', 'top'] : ['top', 'bottom'];
+    }
+
+    function geometry(e) {
+        var a = Doc.node(e.fromNode);
+        var b = Doc.node(e.toNode);
+        if (!a || !b) return null;
+
+        var auto = autoSides(a, b);
+        var fromSide = e.fromSide || auto[0];
+        // A self-loop has no meaningful "facing" side, so it gets a fixed pair
+        // that always produces a visible arc out of and back into the node.
+        var toSide = e.toSide || (a === b ? 'top' : auto[1]);
+
+        var p0 = sideAnchor(a, fromSide);
+        var p3 = sideAnchor(b, toSide);
+        var dist = Math.sqrt((p3.x - p0.x) * (p3.x - p0.x) + (p3.y - p0.y) * (p3.y - p0.y));
+        var k = Math.max(40, dist / 3);
+        return {
+            p0: p0,
+            p3: p3,
+            c1: { x: p0.x + p0.nx * k, y: p0.y + p0.ny * k },
+            c2: { x: p3.x + p3.nx * k, y: p3.y + p3.ny * k }
+        };
+    }
+
+    function curve(g) {
+        return 'M' + g.p0.x + ',' + g.p0.y +
+            'C' + g.c1.x + ',' + g.c1.y + ' ' + g.c2.x + ',' + g.c2.y +
+            ' ' + g.p3.x + ',' + g.p3.y;
+    }
+
+    // midpoint of a cubic at t=0.5, closed form — no DOM measurement needed to
+    // place a label.
+    function midpoint(g) {
+        return {
+            x: (g.p0.x + 3 * g.c1.x + 3 * g.c2.x + g.p3.x) / 8,
+            y: (g.p0.y + 3 * g.c1.y + 3 * g.c2.y + g.p3.y) / 8
+        };
+    }
+
+    // arrowhead draws a triangle with its tip at pt, its base offset along the
+    // outward normal — so the arrow points into the node it terminates on.
+    function arrowhead(pt) {
+        var bx = pt.x + pt.nx * ARROW;
+        var by = pt.y + pt.ny * ARROW;
+        var px = -pt.ny * ARROW * 0.42;
+        var py = pt.nx * ARROW * 0.42;
+        return 'M' + pt.x + ',' + pt.y +
+            'L' + (bx + px) + ',' + (by + py) +
+            'L' + (bx - px) + ',' + (by - py) + 'Z';
+    }
+
+    function colorVar(c) {
+        if (!c) return 'var(--canvas-edge)';
+        if (c.charAt(0) === '#') return c;
+        return 'var(--canvas-' + c + ')';
+    }
+
+    function build(e) {
+        var g = el('g', { 'class': 'canvas-edge' });
+        g.dataset.id = e.id;
+        // A transparent fat stroke under the visible line is the hit target:
+        // a 2px curve is essentially unclickable otherwise.
+        g.appendChild(el('path', { 'class': 'canvas-edge-hit', fill: 'none' }));
+        g.appendChild(el('path', { 'class': 'canvas-edge-line', fill: 'none' }));
+        g.appendChild(el('path', { 'class': 'canvas-edge-head canvas-edge-head-to' }));
+        g.appendChild(el('path', { 'class': 'canvas-edge-head canvas-edge-head-from' }));
+        var label = el('text', { 'class': 'canvas-edge-label', 'text-anchor': 'middle', 'dominant-baseline': 'middle' });
+        g.appendChild(label);
+        return g;
+    }
+
+    function update(g, e) {
+        var geo = geometry(e);
+        if (!geo) { g.setAttribute('display', 'none'); return; }
+        g.removeAttribute('display');
+
+        var d = curve(geo);
+        var stroke = colorVar(e.color);
+        g.querySelector('.canvas-edge-hit').setAttribute('d', d);
+
+        var line = g.querySelector('.canvas-edge-line');
+        line.setAttribute('d', d);
+        line.setAttribute('stroke', stroke);
+
+        // Spec defaults: fromEnd is "none", toEnd is "arrow".
+        var toHead = g.querySelector('.canvas-edge-head-to');
+        if ((e.toEnd || 'arrow') === 'arrow') {
+            toHead.setAttribute('d', arrowhead(geo.p3));
+            toHead.setAttribute('fill', stroke);
+            toHead.removeAttribute('display');
+        } else {
+            toHead.setAttribute('display', 'none');
+        }
+
+        var fromHead = g.querySelector('.canvas-edge-head-from');
+        if ((e.fromEnd || 'none') === 'arrow') {
+            fromHead.setAttribute('d', arrowhead(geo.p0));
+            fromHead.setAttribute('fill', stroke);
+            fromHead.removeAttribute('display');
+        } else {
+            fromHead.setAttribute('display', 'none');
+        }
+
+        var label = g.querySelector('.canvas-edge-label');
+        if (e.label) {
+            var m = midpoint(geo);
+            label.setAttribute('x', m.x);
+            label.setAttribute('y', m.y);
+            label.textContent = e.label;
+            label.removeAttribute('display');
+        } else {
+            label.setAttribute('display', 'none');
+        }
+
+        g.classList.toggle('is-selected', Select.hasEdge(e.id));
+    }
+
+    return {
+        init: function (svgEl) { svg = svgEl; },
+
+        sideAnchor: sideAnchor,
+        autoSides: autoSides,
+
+        render: function () {
+            var seen = {};
+            Doc.edges().forEach(function (e) {
+                seen[e.id] = true;
+                var g = groups[e.id];
+                if (!g) {
+                    g = build(e);
+                    groups[e.id] = g;
+                    svg.appendChild(g);
+                }
+                update(g, e);
+            });
+            Object.keys(groups).forEach(function (id) {
+                if (seen[id]) return;
+                groups[id].remove();
+                delete groups[id];
+            });
+        },
+
+        // syncFor repaints only the edges touching the given nodes. Called on
+        // every frame of a drag, where re-running the full reconcile would be
+        // pure overhead.
+        syncFor: function (nodeIds) {
+            Doc.edgesFor(nodeIds).forEach(function (e) {
+                var g = groups[e.id];
+                if (g) update(g, e);
+            });
+        },
+
+        syncSelection: function () {
+            Doc.edges().forEach(function (e) {
+                var g = groups[e.id];
+                if (g) g.classList.toggle('is-selected', Select.hasEdge(e.id));
+            });
+        },
+
+        // --- rubber band shown while dragging a new edge out of a port ---
+
+        beginTemp: function () {
+            if (temp) temp.remove();
+            temp = el('path', { 'class': 'canvas-edge-temp', fill: 'none' });
+            svg.appendChild(temp);
+        },
+
+        updateTemp: function (node, side, to) {
+            if (!temp) return;
+            var p0 = sideAnchor(node, side);
+            var dist = Math.sqrt((to.x - p0.x) * (to.x - p0.x) + (to.y - p0.y) * (to.y - p0.y));
+            var k = Math.max(40, dist / 3);
+            temp.setAttribute('d',
+                'M' + p0.x + ',' + p0.y +
+                'C' + (p0.x + p0.nx * k) + ',' + (p0.y + p0.ny * k) +
+                ' ' + to.x + ',' + to.y + ' ' + to.x + ',' + to.y);
+        },
+
+        endTemp: function () {
+            if (!temp) return;
+            temp.remove();
+            temp = null;
+        }
+    };
+})();

assets/canvas/edit.js

@@ -0,0 +1,204 @@
+// edit.js — editing a node's content.
+//
+// Text nodes get the vendored CodeMirror editor in place, positioned over the
+// node in *screen* coordinates rather than mounted inside the zoomed world.
+// CodeMirror measures its own layout in device pixels, so a CSS-scaled parent
+// wrecks caret placement and selection maths; a fixed-position panel sidesteps
+// that entirely and stays sharp at every zoom level.
+//
+// The other node types have nothing to type into, so they reuse the existing
+// tree picker and modal instead of an editor.
+window.Canvas = window.Canvas || {};
+
+Canvas.Edit = (function () {
+    var Doc = Canvas.Doc;
+    var View = Canvas.View;
+
+    var MIN_WIDTH = 360;
+    var MIN_HEIGHT = 200;
+
+    var panel = null;
+    var view = null;
+    var currentId = null;
+    var original = '';
+
+    function destroy() {
+        if (view) { view.destroy(); view = null; }
+        if (panel) { panel.remove(); panel = null; }
+        currentId = null;
+        original = '';
+        document.removeEventListener('pointerdown', onOutside, true);
+    }
+
+    function commit() {
+        if (!panel || !view) return;
+        var text = view.state.doc.toString();
+        var id = currentId;
+        destroy();
+        var n = Doc.node(id);
+        if (!n || text === original) return;
+        Doc.begin('edit text');
+        n.text = text;
+        Doc.commit();
+    }
+
+    function onOutside(e) {
+        if (!panel || panel.contains(e.target)) return;
+        commit();
+    }
+
+    // screenRect places the editor over the node it edits, clamped to a usable
+    // minimum and kept inside the viewport — a 60x60 node still needs a panel
+    // big enough to type in.
+    function screenRect(n) {
+        var s = View.scale();
+        var tl = View.toScreen(n.x, n.y);
+        var w = Math.max(MIN_WIDTH, n.width * s);
+        var h = Math.max(MIN_HEIGHT, n.height * s);
+        w = Math.min(w, window.innerWidth - 16);
+        h = Math.min(h, window.innerHeight - 16);
+        var left = Math.max(8, Math.min(tl.x, window.innerWidth - w - 8));
+        var top = Math.max(8, Math.min(tl.y, window.innerHeight - h - 8));
+        return { left: left, top: top, width: w, height: h };
+    }
+
+    function openText(n) {
+        var rect = screenRect(n);
+        panel = document.createElement('div');
+        panel.className = 'canvas-editor panel panel-floating';
+        panel.style.left = rect.left + 'px';
+        panel.style.top = rect.top + 'px';
+        panel.style.width = rect.width + 'px';
+        panel.style.height = rect.height + 'px';
+
+        var hint = document.createElement('div');
+        hint.className = 'panel-header';
+        hint.textContent = 'Ctrl+Enter or click away to apply · Escape to cancel';
+        panel.appendChild(hint);
+
+        var mount = document.createElement('div');
+        mount.className = 'canvas-editor-mount';
+        panel.appendChild(mount);
+        document.body.appendChild(panel);
+
+        currentId = n.id;
+        original = n.text || '';
+
+        view = new CM.EditorView({
+            state: CM.EditorState.create({
+                doc: original,
+                selection: { anchor: original.length },
+                extensions: [
+                    CM.history(),
+                    CM.drawSelection(),
+                    CM.indentOnInput(),
+                    CM.EditorView.lineWrapping,
+                    CM.EditorView.contentAttributes.of({ spellcheck: 'true', autocapitalize: 'sentences' }),
+                    CM.markdown({ base: CM.markdownLanguage }),
+                    CM.syntaxHighlighting(CM.highlightStyle),
+                    CM.closeBrackets(),
+                    CM.autocompletion({ override: [WikiComplete.source] }),
+                    CM.theme,
+                    // Mod-Enter goes first (nothing else claims it); Escape goes
+                    // last so an open completion popup still gets first refusal
+                    // on it and closes itself instead of discarding the edit.
+                    CM.keymap.of([{ key: 'Mod-Enter', run: function () { commit(); return true; } }]
+                        .concat(
+                            CM.closeBracketsKeymap,
+                            CM.completionKeymap,
+                            CM.markdownKeymap,
+                            CM.defaultKeymap,
+                            CM.historyKeymap,
+                            [CM.indentWithTab],
+                            [{ key: 'Escape', run: function () { destroy(); return true; } }]
+                        ))
+                ]
+            }),
+            parent: mount
+        });
+        view.focus();
+        // Capture phase: a click on a toolbar button should apply the edit
+        // before that button's own handler reads the document.
+        document.addEventListener('pointerdown', onOutside, true);
+    }
+
+    function openFile(n) {
+        var start = (n.file || '/').replace(/\/+$/, '') || '/';
+        openTreePicker({
+            title: 'File node — pick a target',
+            mode: 'any',
+            initialPath: start,
+            preselect: start,
+            confirmLabel: 'USE',
+            onSelect: function (p) {
+                if (!p || p === n.file) return;
+                Doc.begin('retarget file node');
+                n.file = p;
+                n.subpath = '';
+                Doc.commit();
+            }
+        });
+    }
+
+    function promptValue(title, label, value, onValue) {
+        var input = document.createElement('input');
+        input.type = 'text';
+        input.className = 'input';
+        input.placeholder = label;
+        input.value = value || '';
+        openModal({
+            title: title,
+            body: input,
+            confirm: {
+                label: 'OK',
+                onConfirm: function () {
+                    closeModal();
+                    onValue(input.value.trim());
+                }
+            }
+        });
+    }
+
+    function openLink(n) {
+        promptValue('Link node', 'https://example.com', n.url, function (v) {
+            if (!v || v === n.url) return;
+            Doc.begin('edit link');
+            n.url = v;
+            Doc.commit();
+        });
+    }
+
+    function openGroup(n) {
+        promptValue('Group label', 'Label', n.label, function (v) {
+            if (v === (n.label || '')) return;
+            Doc.begin('edit group label');
+            if (v) n.label = v; else delete n.label;
+            Doc.commit();
+        });
+    }
+
+    // close applies whatever is currently open, if anything.
+    function close() {
+        if (panel) commit();
+    }
+
+    return {
+        open: function (id) {
+            var n = Doc.node(id);
+            if (!n) return;
+            close();
+            switch (n.type) {
+                case 'text': openText(n); break;
+                case 'file': openFile(n); break;
+                case 'link': openLink(n); break;
+                case 'group': openGroup(n); break;
+            }
+        },
+
+        // Called from the gesture layer on any pointerdown on the surface, so
+        // starting a drag never silently drops an edit.
+        close: close,
+
+        isOpen: function () { return panel !== null; }
+    };
+})();

assets/canvas/interact.js

@@ -0,0 +1,461 @@
+// interact.js — pointer and keyboard gestures.
+//
+// Every gesture is bracketed by Doc.begin()/Doc.commit(), so a drag that spans
+// hundreds of pointermove events collapses into one undo entry. Within a
+// gesture the document is mutated directly and only the affected elements are
+// re-synced; the full reconcile happens once, on commit.
+//
+// Gesture routing on pointerdown, in priority order:
+//   resize handle -> resize        port -> draw an edge
+//   node          -> select + drag edge -> select
+//   background    -> pan (shift: marquee select; two fingers: pinch zoom)
+window.Canvas = window.Canvas || {};
+
+Canvas.Interact = (function () {
+    var Doc = Canvas.Doc;
+    var View = Canvas.View;
+    var Select = Canvas.Select;
+    var Nodes = Canvas.Nodes;
+    var Edges = Canvas.Edges;
+
+    var MIN_SIZE = 40;
+    var DRAG_SLOP = 3;
+
+    var surface = null;
+    var marquee = null;
+    var gesture = null;
+    var pointers = {};
+
+    function snap(v) {
+        return Math.round(v / View.GRID) * View.GRID;
+    }
+
+    function pointerCount() {
+        return Object.keys(pointers).length;
+    }
+
+    // interactive reports whether the pointer landed on something the browser
+    // should handle itself (a link, a video control), which must not become the
+    // start of a node drag.
+    function interactive(target) {
+        return !!target.closest('a, button, input, select, textarea, video, embed, iframe');
+    }
+
+    // groupMembers returns the nodes whose centre sits inside a group, which is
+    // what "inside" means for dragging: a node straddling the border belongs to
+    // whichever side holds most of it.
+    function groupMembers(g) {
+        return Doc.nodes().filter(function (n) {
+            if (n.id === g.id) return false;
+            var cx = n.x + n.width / 2;
+            var cy = n.y + n.height / 2;
+            return cx >= g.x && cx <= g.x + g.width && cy >= g.y && cy <= g.y + g.height;
+        }).map(function (n) { return n.id; });
+    }
+
+    // withGroupMembers expands a selection so dragging a group carries whatever
+    // it contains.
+    function withGroupMembers(ids) {
+        var out = {};
+        ids.forEach(function (id) {
+            out[id] = true;
+            var n = Doc.node(id);
+            if (n && n.type === 'group') {
+                groupMembers(n).forEach(function (m) { out[m] = true; });
+            }
+        });
+        return Object.keys(out);
+    }
+
+    function selectOnPress(id, additive) {
+        if (additive) {
+            Select.toggleNode(id);
+            return;
+        }
+        if (!Select.hasNode(id)) Select.set([id], []);
+    }
+
+    // --- gesture starts ---
+
+    function startDrag(id, e) {
+        selectOnPress(id, e.shiftKey);
+        if (!Select.hasNode(id)) return; // shift-click deselected it
+        var ids = withGroupMembers(Select.nodes());
+        Doc.begin('move');
+        gesture = {
+            kind: 'drag',
+            ids: ids,
+            start: View.toWorld(e.clientX, e.clientY),
+            origin: ids.map(function (nid) {
+                var n = Doc.node(nid);
+                return { id: nid, x: n.x, y: n.y };
+            }),
+            moved: false
+        };
+    }
+
+    function startResize(id, corner, e) {
+        Select.set([id], []);
+        var n = Doc.node(id);
+        Doc.begin('resize');
+        gesture = {
+            kind: 'resize',
+            id: id,
+            corner: corner,
+            start: View.toWorld(e.clientX, e.clientY),
+            origin: { x: n.x, y: n.y, width: n.width, height: n.height },
+            moved: false
+        };
+    }
+
+    function startEdge(id, side) {
+        Edges.beginTemp();
+        gesture = { kind: 'edge', fromId: id, fromSide: side, target: null, moved: false };
+    }
+
+    function startPan(e) {
+        gesture = { kind: 'pan', last: { x: e.clientX, y: e.clientY }, moved: false };
+    }
+
+    function startMarquee(e) {
+        var r = surface.getBoundingClientRect();
+        gesture = {
+            kind: 'marquee',
+            origin: { x: e.clientX - r.left, y: e.clientY - r.top },
+            additive: e.ctrlKey || e.metaKey,
+            moved: false
+        };
+        marquee.hidden = false;
+        updateMarquee(e);
+    }
+
+    function startPinch() {
+        var ids = Object.keys(pointers);
+        var a = pointers[ids[0]];
+        var b = pointers[ids[1]];
+        gesture = {
+            kind: 'pinch',
+            dist: Math.hypot(b.x - a.x, b.y - a.y),
+            mid: { x: (a.x + b.x) / 2, y: (a.y + b.y) / 2 },
+            moved: true
+        };
+    }
+
+    // --- gesture updates ---
+
+    function moveDrag(e) {
+        var p = View.toWorld(e.clientX, e.clientY);
+        var lead = gesture.origin[0];
+        if (!lead) return;
+        var dx = p.x - gesture.start.x;
+        var dy = p.y - gesture.start.y;
+        // Snap the lead node to the grid and shift the rest by the same amount,
+        // so a multi-node drag keeps its relative layout. Alt opts out.
+        if (!e.altKey) {
+            dx = snap(lead.x + dx) - lead.x;
+            dy = snap(lead.y + dy) - lead.y;
+        }
+        gesture.origin.forEach(function (o) {
+            var n = Doc.node(o.id);
+            if (!n) return;
+            n.x = Math.round(o.x + dx);
+            n.y = Math.round(o.y + dy);
+        });
+        gesture.ids.forEach(Nodes.syncGeom);
+        Edges.syncFor(gesture.ids);
+    }
+
+    function moveResize(e) {
+        var n = Doc.node(gesture.id);
+        if (!n) return;
+        var p = View.toWorld(e.clientX, e.clientY);
+        var o = gesture.origin;
+        var dx = p.x - gesture.start.x;
+        var dy = p.y - gesture.start.y;
+        var right = o.x + o.width;
+        var bottom = o.y + o.height;
+        var x = o.x, y = o.y, w = o.width, h = o.height;
+
+        if (gesture.corner.indexOf('w') !== -1) {
+            x = e.altKey ? o.x + dx : snap(o.x + dx);
+            w = right - x;
+        } else {
+            w = e.altKey ? o.width + dx : snap(right + dx) - o.x;
+        }
+        if (gesture.corner.indexOf('n') !== -1) {
+            y = e.altKey ? o.y + dy : snap(o.y + dy);
+            h = bottom - y;
+        } else {
+            h = e.altKey ? o.height + dy : snap(bottom + dy) - o.y;
+        }
+
+        // Clamp against the fixed edge so shrinking past the minimum pins the
+        // node instead of flipping it inside out.
+        if (w < MIN_SIZE) {
+            if (gesture.corner.indexOf('w') !== -1) x = right - MIN_SIZE;
+            w = MIN_SIZE;
+        }
+        if (h < MIN_SIZE) {
+            if (gesture.corner.indexOf('n') !== -1) y = bottom - MIN_SIZE;
+            h = MIN_SIZE;
+        }
+
+        n.x = Math.round(x);
+        n.y = Math.round(y);
+        n.width = Math.round(w);
+        n.height = Math.round(h);
+        Nodes.syncGeom(n.id);
+        Edges.syncFor([n.id]);
+    }
+
+    function moveEdge(e) {
+        var from = Doc.node(gesture.fromId);
+        if (!from) return;
+        Edges.updateTemp(from, gesture.fromSide, View.toWorld(e.clientX, e.clientY));
+
+        var under = document.elementFromPoint(e.clientX, e.clientY);
+        var nodeEl = under && under.closest ? under.closest('.canvas-node') : null;
+        var id = nodeEl ? nodeEl.dataset.id : null;
+        if (id === gesture.target) return;
+        if (gesture.target) {
+            var prev = Nodes.el(gesture.target);
+            if (prev) prev.classList.remove('is-edge-target');
+        }
+        gesture.target = id;
+        if (id && nodeEl) nodeEl.classList.add('is-edge-target');
+    }
+
+    function updateMarquee(e) {
+        var r = surface.getBoundingClientRect();
+        var x = e.clientX - r.left;
+        var y = e.clientY - r.top;
+        marquee.style.left = Math.min(x, gesture.origin.x) + 'px';
+        marquee.style.top = Math.min(y, gesture.origin.y) + 'px';
+        marquee.style.width = Math.abs(x - gesture.origin.x) + 'px';
+        marquee.style.height = Math.abs(y - gesture.origin.y) + 'px';
+    }
+
+    function movePinch() {
+        var ids = Object.keys(pointers);
+        if (ids.length < 2) return;
+        var a = pointers[ids[0]];
+        var b = pointers[ids[1]];
+        var dist = Math.hypot(b.x - a.x, b.y - a.y);
+        var mid = { x: (a.x + b.x) / 2, y: (a.y + b.y) / 2 };
+        if (gesture.dist > 0) View.zoomAt(mid.x, mid.y, dist / gesture.dist);
+        View.pan(mid.x - gesture.mid.x, mid.y - gesture.mid.y);
+        gesture.dist = dist;
+        gesture.mid = mid;
+    }
+
+    // --- gesture ends ---
+
+    // Both finishers take the gesture as an argument rather than reading the
+    // module-level one: endGesture clears it before dispatching so a finisher
+    // cannot accidentally leave a half-torn-down gesture in place.
+    function finishMarquee(g) {
+        marquee.hidden = true;
+        var r = surface.getBoundingClientRect();
+        var a = View.toWorld(r.left + parseFloat(marquee.style.left),
+            r.top + parseFloat(marquee.style.top));
+        var b = View.toWorld(r.left + parseFloat(marquee.style.left) + parseFloat(marquee.style.width),
+            r.top + parseFloat(marquee.style.top) + parseFloat(marquee.style.height));
+        var hit = Doc.nodes().filter(function (n) {
+            return n.x < b.x && n.x + n.width > a.x && n.y < b.y && n.y + n.height > a.y;
+        }).map(function (n) { return n.id; });
+        if (g.additive) {
+            hit.forEach(Select.addNode);
+        } else {
+            Select.set(hit, []);
+        }
+    }
+
+    function finishEdge(g) {
+        if (g.target) {
+            var el = Nodes.el(g.target);
+            if (el) el.classList.remove('is-edge-target');
+        }
+        Edges.endTemp();
+        if (!g.target) return;
+        Doc.begin('connect');
+        Doc.addEdge({
+            id: Doc.newId(),
+            fromNode: g.fromId,
+            fromSide: g.fromSide,
+            toNode: g.target
+        });
+        Doc.commit();
+    }
+
+    // --- event wiring ---
+
+    function onDown(e) {
+        if (Canvas.Edit) Canvas.Edit.close();
+        pointers[e.pointerId] = { x: e.clientX, y: e.clientY };
+
+        if (pointerCount() === 2 && (!gesture || gesture.kind === 'pan')) {
+            if (gesture) endGesture(true);
+            startPinch();
+            return;
+        }
+        if (gesture) return; // one gesture at a time
+
+        var t = e.target;
+        var handle = t.closest('.canvas-handle');
+        var port = t.closest('.canvas-port');
+        var nodeEl = t.closest('.canvas-node');
+        var edgeEl = t.closest('.canvas-edge');
+
+        if (handle && nodeEl) {
+            startResize(nodeEl.dataset.id, handle.dataset.corner, e);
+        } else if (port && nodeEl) {
+            startEdge(nodeEl.dataset.id, port.dataset.side);
+        } else if (nodeEl) {
+            if (interactive(t)) return;
+            startDrag(nodeEl.dataset.id, e);
+        } else if (edgeEl) {
+            if (e.shiftKey) Select.toggleEdge(edgeEl.dataset.id);
+            else Select.set([], [edgeEl.dataset.id]);
+            return;
+        } else if (e.shiftKey) {
+            startMarquee(e);
+        } else {
+            startPan(e);
+        }
+
+        if (gesture) {
+            // Capture keeps the gesture alive when the pointer leaves the
+            // surface mid-drag. It throws when the pointer is already gone (a
+            // release that raced the handler), which must not abort the
+            // gesture — that would leave it stuck with no pointerup to end it.
+            try { surface.setPointerCapture(e.pointerId); } catch (err) { /* pointer already released */ }
+            e.preventDefault();
+        }
+    }
+
+    function onMove(e) {
+        if (pointers[e.pointerId]) {
+            pointers[e.pointerId].x = e.clientX;
+            pointers[e.pointerId].y = e.clientY;
+        }
+        if (!gesture) return;
+
+        if (gesture.kind === 'pinch') { movePinch(); return; }
+
+        if (!gesture.moved) {
+            // Ignore sub-pixel jitter so a plain click does not register as a
+            // drag (and so a click on the background still clears the selection).
+            var dx = Math.abs(e.movementX || 0);
+            var dy = Math.abs(e.movementY || 0);
+            if (dx + dy < DRAG_SLOP && gesture.kind !== 'edge') return;
+            gesture.moved = true;
+        }
+
+        switch (gesture.kind) {
+            case 'drag': moveDrag(e); break;
+            case 'resize': moveResize(e); break;
+            case 'edge': moveEdge(e); break;
+            case 'marquee': updateMarquee(e); break;
+            case 'pan':
+                View.pan(e.clientX - gesture.last.x, e.clientY - gesture.last.y);
+                gesture.last = { x: e.clientX, y: e.clientY };
+                break;
+        }
+    }
+
+    function endGesture(silent) {
+        if (!gesture) return;
+        var g = gesture;
+        gesture = null;
+        switch (g.kind) {
+            case 'drag':
+            case 'resize':
+                Doc.commit();
+                break;
+            case 'edge':
+                if (!silent) finishEdge(g); else Edges.endTemp();
+                break;
+            case 'marquee':
+                if (!silent) finishMarquee(g); else marquee.hidden = true;
+                break;
+            case 'pan':
+                // A press on the background that never moved is a click, and a
+                // click on empty space clears the selection.
+                if (!silent && !g.moved) Select.clear();
+                break;
+        }
+    }
+
+    function onUp(e) {
+        delete pointers[e.pointerId];
+        if (gesture && gesture.kind === 'pinch' && pointerCount() < 2) {
+            gesture = null;
+            return;
+        }
+        endGesture(false);
+    }
+
+    function onWheel(e) {
+        // Ctrl/meta+wheel is the zoom gesture every drawing tool uses, and is
+        // also what a trackpad pinch reports. A plain wheel scrolls the canvas.
+        if (e.ctrlKey || e.metaKey) {
+            e.preventDefault();
+            View.zoomAt(e.clientX, e.clientY, Math.pow(0.999, e.deltaY));
+            return;
+        }
+        e.preventDefault();
+        if (e.shiftKey) View.pan(-e.deltaY, 0);
+        else View.pan(-e.deltaX, -e.deltaY);
+    }
+
+    function onDblClick(e) {
+        var nodeEl = e.target.closest('.canvas-node');
+        if (nodeEl) {
+            if (interactive(e.target)) return;
+            e.preventDefault();
+            Canvas.Edit.open(nodeEl.dataset.id);
+            return;
+        }
+        if (e.target.closest('.canvas-edge')) return;
+        // Double-clicking empty space drops a new text node there and opens it,
+        // which is how a canvas normally gets its first node.
+        var p = View.toWorld(e.clientX, e.clientY);
+        var node = Canvas.Actions.addText(p);
+        if (node) Canvas.Edit.open(node.id);
+    }
+
+    return {
+        init: function (surfaceEl, marqueeEl) {
+            surface = surfaceEl;
+            marquee = marqueeEl;
+
+            surface.addEventListener('pointerdown', onDown);
+            surface.addEventListener('pointermove', onMove);
+            surface.addEventListener('pointerup', onUp);
+            surface.addEventListener('pointercancel', onUp);
+            surface.addEventListener('wheel', onWheel, { passive: false });
+            surface.addEventListener('dblclick', onDblClick);
+            // Native drag would fight the pointer gestures on images and links.
+            surface.addEventListener('dragstart', function (e) { e.preventDefault(); });
+            surface.addEventListener('contextmenu', function (e) {
+                if (e.target.closest('.canvas-node, .canvas-edge')) e.preventDefault();
+            });
+        },
+
+        // cancel aborts an in-flight gesture and rolls the document back, for
+        // the Escape key.
+        cancel: function () {
+            if (!gesture) return false;
+            var kind = gesture.kind;
+            if (kind === 'drag' || kind === 'resize') {
+                gesture = null;
+                Doc.abort();
+                return true;
+            }
+            endGesture(true);
+            return true;
+        },
+
+        active: function () { return gesture !== null; }
+    };
+})();

assets/canvas/main.html

@@ -0,0 +1,88 @@
+{{define "headerActions"}}
+<a class="btn" href="{{.PostURL}}" title="Back to the page">PAGE</a>
+<span class="dropdown">
+    <button type="button" class="btn dropdown-toggle" data-action="canvas-menu" title="Canvas actions">CANVAS▾</button>
+    <div class="dropdown-menu align-right">
+        <button type="button" class="btn btn-block" data-action="canvas-rename">Rename…</button>
+        <button type="button" class="btn btn-block danger" data-action="canvas-delete">Delete canvas</button>
+    </div>
+</span>
+<button class="btn" type="button" data-action="canvas-save" title="Save (Ctrl+S)">SAVE</button>
+{{end}}
+
+{{define "content"}}
+<script>
+    // Full-bleed view mode: the canvas surface owns the viewport instead of the
+    // centred reading column. Set here rather than server-side for the same
+    // reason the editor does it — one class, no extra template plumbing.
+    document.body.classList.add('canvas-mode');
+</script>
+{{if .CanvasError}}
+<div class="content">
+    <h1>{{.ActiveCanvas}}</h1>
+    <p class="canvas-broken">This canvas could not be opened — {{.CanvasError}}</p>
+    <p>Fix it in the file itself, then reload.
+       <a href="{{.ActiveCanvas}}.canvas?raw">view the raw file</a> ·
+       <a href="{{.PostURL}}">back to the page</a></p>
+</div>
+{{else}}
+<div class="canvas-app">
+    <nav class="canvas-tabs row" aria-label="Page views">
+        <a class="canvas-tab" href="{{.PostURL}}">PAGE</a>
+        {{range .Canvases}}<a class="canvas-tab{{if .Active}} is-active{{end}}" href="{{.URL}}">{{.Name}}</a>{{end}}
+    </nav>
+    <div class="canvas-toolbar row">
+        <button type="button" class="btn btn-tool" data-action="undo" title="Undo (Ctrl+Z)" disabled>↶</button>
+        <button type="button" class="btn btn-tool" data-action="redo" title="Redo (Ctrl+Shift+Z)" disabled>↷</button>
+        <span class="toolbar-sep"></span>
+        <button type="button" class="btn btn-tool" data-action="add-text" title="Add text node (T)">TEXT</button>
+        <button type="button" class="btn btn-tool" data-action="add-file" title="Add file node (F)">FILE</button>
+        <button type="button" class="btn btn-tool" data-action="add-link" title="Add link node (L)">LINK</button>
+        <button type="button" class="btn btn-tool" data-action="add-group" title="Add group (G)">GROUP</button>
+        <span class="toolbar-sep"></span>
+        <span class="dropdown">
+            <button type="button" class="btn btn-tool dropdown-toggle" data-action="color-menu" title="Colour of the selection">■▾</button>
+            <div class="dropdown-menu canvas-color-menu">
+                <button type="button" class="btn btn-tool btn-block" data-color="">Default</button>
+                <button type="button" class="btn btn-tool btn-block" data-color="1"><span class="canvas-swatch" data-swatch="1"></span> Red</button>
+                <button type="button" class="btn btn-tool btn-block" data-color="2"><span class="canvas-swatch" data-swatch="2"></span> Orange</button>
+                <button type="button" class="btn btn-tool btn-block" data-color="3"><span class="canvas-swatch" data-swatch="3"></span> Yellow</button>
+                <button type="button" class="btn btn-tool btn-block" data-color="4"><span class="canvas-swatch" data-swatch="4"></span> Green</button>
+                <button type="button" class="btn btn-tool btn-block" data-color="5"><span class="canvas-swatch" data-swatch="5"></span> Cyan</button>
+                <button type="button" class="btn btn-tool btn-block" data-color="6"><span class="canvas-swatch" data-swatch="6"></span> Purple</button>
+            </div>
+        </span>
+        <button type="button" class="btn btn-tool" data-action="delete-selection" title="Delete selection (Del)">×</button>
+        <span class="toolbar-sep"></span>
+        <button type="button" class="btn btn-tool" data-action="zoom-out" title="Zoom out (−)">−</button>
+        <button type="button" class="btn btn-tool" data-action="zoom-reset" title="Reset zoom to 100% (0)"><span data-canvas-zoom>100%</span></button>
+        <button type="button" class="btn btn-tool" data-action="zoom-in" title="Zoom in (+)">+</button>
+        <button type="button" class="btn btn-tool" data-action="fit" title="Fit to content (9)">FIT</button>
+        <span class="canvas-status muted" data-canvas-status></span>
+    </div>
+    <div class="canvas-surface" id="canvas-surface" tabindex="0">
+        <div class="canvas-world" id="canvas-world">
+            <div class="canvas-layer" id="canvas-groups"></div>
+            <svg class="canvas-edges" id="canvas-edges" xmlns="http://www.w3.org/2000/svg"></svg>
+            <div class="canvas-layer" id="canvas-nodes"></div>
+        </div>
+        <div class="canvas-marquee" id="canvas-marquee" hidden></div>
+        <div class="canvas-hint muted" data-canvas-hint hidden>
+            Empty canvas — use the toolbar to add a node. Drag the background to pan, ctrl+wheel to zoom.
+        </div>
+    </div>
+</div>
+<script>window.CANVAS_DATA = {{.CanvasJSON}};</script>
+<script src="/_/editor/vendor/codemirror.bundle.js?v={{editorBundleVersion}}"></script>
+<script src="/_/editor/wikicomplete.js"></script>
+<script src="/_/canvas/doc.js"></script>
+<script src="/_/canvas/view.js"></script>
+<script src="/_/canvas/select.js"></script>
+<script src="/_/canvas/nodes.js"></script>
+<script src="/_/canvas/edges.js"></script>
+<script src="/_/canvas/interact.js"></script>
+<script src="/_/canvas/edit.js"></script>
+<script src="/_/canvas/save.js"></script>
+<script src="/_/canvas/main.js"></script>
+{{end}}
+{{end}}

assets/canvas/main.js

@@ -0,0 +1,389 @@
+// main.js — bootstrap, toolbar, and keyboard shortcuts.
+//
+// The payload the server inlined (document + pre-rendered node HTML + the
+// version token) is the only input; nothing else is fetched on load.
+(function () {
+    var data = window.CANVAS_DATA;
+    var surface = document.getElementById('canvas-surface');
+    if (!data || !surface) return;
+
+    var Doc = Canvas.Doc;
+    var View = Canvas.View;
+    var Select = Canvas.Select;
+    var Nodes = Canvas.Nodes;
+    var Edges = Canvas.Edges;
+    var Save = Canvas.Save;
+
+    var world = document.getElementById('canvas-world');
+    var marquee = document.getElementById('canvas-marquee');
+    var hint = document.querySelector('[data-canvas-hint]');
+    var statusEl = document.querySelector('[data-canvas-status]');
+    var zoomEl = document.querySelector('[data-canvas-zoom]');
+
+    // Default sizes for new nodes, in world pixels. Multiples of the 20px grid
+    // so a fresh node lands aligned.
+    var SIZES = {
+        text: { width: 260, height: 120 },
+        file: { width: 400, height: 400 },
+        link: { width: 400, height: 140 },
+        group: { width: 520, height: 400 }
+    };
+
+    function snap(v) { return Math.round(v / View.GRID) * View.GRID; }
+
+    // --- document actions ---
+
+    Canvas.Actions = {
+        // add drops a node centred on a world point (the viewport centre when
+        // called from the toolbar, the cursor when called from a double-click).
+        add: function (type, extra, at) {
+            var size = SIZES[type];
+            var p = at || View.centreOfViewport();
+            var node = {
+                id: Doc.newId(),
+                type: type,
+                x: snap(p.x - size.width / 2),
+                y: snap(p.y - size.height / 2),
+                width: size.width,
+                height: size.height
+            };
+            for (var k in extra) {
+                if (Object.prototype.hasOwnProperty.call(extra, k)) node[k] = extra[k];
+            }
+            Doc.begin('add ' + type);
+            Doc.addNode(node);
+            Doc.commit();
+            Select.set([node.id], []);
+            return node;
+        },
+
+        addText: function (at) {
+            return Canvas.Actions.add('text', { text: '' }, at);
+        },
+
+        addGroup: function (at) {
+            return Canvas.Actions.add('group', { label: 'Group' }, at);
+        },
+
+        // A file node is meaningless without a target and a link node without a
+        // url, so both ask first and only then create — validation on the server
+        // rejects the empty forms anyway.
+        addFile: function () {
+            openTreePicker({
+                title: 'File node — pick a target',
+                mode: 'any',
+                initialPath: data.postUrl,
+                confirmLabel: 'ADD',
+                onSelect: function (p) {
+                    if (p) Canvas.Actions.add('file', { file: p });
+                }
+            });
+        },
+
+        addLink: function () {
+            var input = document.createElement('input');
+            input.type = 'url';
+            input.className = 'input';
+            input.placeholder = 'https://example.com';
+            openModal({
+                title: 'Link node',
+                body: input,
+                confirm: {
+                    label: 'ADD',
+                    onConfirm: function () {
+                        var v = input.value.trim();
+                        if (!v) return;
+                        closeModal();
+                        Canvas.Actions.add('link', { url: v });
+                    }
+                }
+            });
+        },
+
+        deleteSelection: function () {
+            if (Select.isEmpty()) return;
+            Doc.begin('delete');
+            Doc.remove(Select.nodes(), Select.edges());
+            Doc.commit();
+            Select.clear();
+        },
+
+        setColor: function (color) {
+            if (Select.isEmpty()) return;
+            Doc.begin('colour');
+            Select.nodes().forEach(function (id) {
+                var n = Doc.node(id);
+                if (!n) return;
+                if (color) n.color = color; else delete n.color;
+            });
+            Select.edges().forEach(function (id) {
+                var e = Doc.edge(id);
+                if (!e) return;
+                if (color) e.color = color; else delete e.color;
+            });
+            Doc.commit();
+        },
+
+        // nudge moves the selection by whole grid steps, or single pixels with
+        // shift held for the cases where the grid is in the way.
+        nudge: function (dx, dy, fine) {
+            var ids = Select.nodes();
+            if (!ids.length) return;
+            var step = fine ? 1 : View.GRID;
+            Doc.begin('nudge');
+            ids.forEach(function (id) {
+                var n = Doc.node(id);
+                if (!n) return;
+                n.x += dx * step;
+                n.y += dy * step;
+            });
+            Doc.commit();
+        },
+
+        selectAll: function () {
+            Select.set(
+                Doc.nodes().map(function (n) { return n.id; }),
+                Doc.edges().map(function (e) { return e.id; })
+            );
+        }
+    };
+
+    // --- chrome ---
+
+    function setStatus(text) {
+        if (statusEl) statusEl.textContent = text || '';
+    }
+
+    function updateToolbar() {
+        var undoBtn = document.querySelector('[data-action="undo"]');
+        var redoBtn = document.querySelector('[data-action="redo"]');
+        var delBtn = document.querySelector('[data-action="delete-selection"]');
+        if (undoBtn) undoBtn.disabled = !Doc.canUndo();
+        if (redoBtn) redoBtn.disabled = !Doc.canRedo();
+        if (delBtn) delBtn.disabled = Select.isEmpty();
+
+        var saveBtn = document.querySelector('[data-action="canvas-save"]');
+        if (saveBtn) saveBtn.classList.toggle('is-active', Doc.isDirty());
+        if (hint) hint.hidden = Doc.nodes().length > 0;
+    }
+
+    function updateZoom() {
+        if (zoomEl) zoomEl.textContent = Math.round(View.scale() * 100) + '%';
+    }
+
+    // refresh is the single re-render path: prune the selection against the
+    // (possibly undone) document, reconcile both layers, update the chrome.
+    function refresh() {
+        Select.prune(Doc.get());
+        Nodes.render();
+        Edges.render();
+        updateToolbar();
+    }
+
+    // --- canvas-level actions (rename / delete the file itself) ---
+
+    function leaveGuard() {
+        if (!Doc.isDirty()) return true;
+        return window.confirm('This canvas has unsaved changes. Leave anyway?');
+    }
+
+    function canvasAction(url, then) {
+        fetch(url, { method: 'POST', credentials: 'same-origin', redirect: 'manual' })
+            .then(function (res) {
+                if (res.type === 'opaqueredirect' || res.ok) { then(); return; }
+                return res.text().then(function (msg) {
+                    alert(msg || ('Request failed (' + res.status + ')'));
+                });
+            })
+            .catch(function () { alert('Network error'); });
+    }
+
+    function renameCanvas() {
+        var input = document.createElement('input');
+        input.type = 'text';
+        input.className = 'input';
+        input.value = data.name;
+        openModal({
+            title: 'Rename canvas',
+            body: input,
+            confirm: {
+                label: 'RENAME',
+                onConfirm: function () {
+                    var v = input.value.trim();
+                    if (!v || v === data.name) { closeModal(); return; }
+                    closeModal();
+                    canvasAction(
+                        data.postUrl + '?canvas=' + encodeURIComponent(data.name) +
+                        '&rename=' + encodeURIComponent(v),
+                        function () {
+                            window.location.href = data.postUrl + '?canvas=' + encodeURIComponent(v);
+                        }
+                    );
+                }
+            }
+        });
+    }
+
+    function deleteCanvas() {
+        openModal({
+            title: 'Delete canvas',
+            body: 'Delete "' + data.name + '"? The page itself is not affected.',
+            confirm: {
+                label: 'DELETE',
+                danger: true,
+                onConfirm: function () {
+                    closeModal();
+                    canvasAction(
+                        data.postUrl + '?canvas=' + encodeURIComponent(data.name) + '&delete=1',
+                        function () { window.location.href = data.postUrl; }
+                    );
+                }
+            }
+        });
+    }
+
+    // --- wiring ---
+
+    function wireToolbar() {
+        var handlers = {
+            'undo': function () { Doc.undo(); },
+            'redo': function () { Doc.redo(); },
+            'add-text': function () { Canvas.Edit.open(Canvas.Actions.addText().id); },
+            'add-file': function () { Canvas.Actions.addFile(); },
+            'add-link': function () { Canvas.Actions.addLink(); },
+            'add-group': function () { Canvas.Actions.addGroup(); },
+            'delete-selection': function () { Canvas.Actions.deleteSelection(); },
+            'zoom-in': function () { View.zoomBy(1.2); },
+            'zoom-out': function () { View.zoomBy(1 / 1.2); },
+            'zoom-reset': function () { View.resetZoom(); },
+            'fit': function () { View.fit(Doc.nodes()); },
+            'canvas-save': function () { Save.run(); },
+            'canvas-rename': renameCanvas,
+            'canvas-delete': deleteCanvas
+        };
+
+        document.addEventListener('click', function (e) {
+            var btn = e.target.closest('[data-action]');
+            if (!btn) return;
+            var fn = handlers[btn.dataset.action];
+            if (!fn) return;
+            e.preventDefault();
+            fn();
+        });
+
+        document.querySelectorAll('.canvas-color-menu [data-color]').forEach(function (btn) {
+            btn.addEventListener('click', function () {
+                Canvas.Actions.setColor(btn.dataset.color);
+            });
+        });
+
+        // The header dropdowns are wired on demand: the auto-wiring in
+        // global-shortcuts.js only covers the page's ACTIONS menu, which this
+        // view replaces.
+        ['canvas-menu', 'color-menu'].forEach(function (action) {
+            wireDropdown(document.querySelector('[data-action="' + action + '"]'));
+        });
+
+        document.querySelectorAll('.canvas-tabs a').forEach(function (a) {
+            a.addEventListener('click', function (e) {
+                if (!leaveGuard()) e.preventDefault();
+            });
+        });
+    }
+
+    // typing reports whether the keystroke belongs to a text field, an open
+    // modal, or the node editor — in which case the canvas must keep its hands
+    // off it.
+    function typing(e) {
+        var t = e.target;
+        if (!t || !t.closest) return false;
+        return !!t.closest('input, textarea, select, .cm-editor, .modal, [contenteditable="true"]');
+    }
+
+    function wireKeys() {
+        document.addEventListener('keydown', function (e) {
+            if (typing(e)) return;
+
+            var mod = e.ctrlKey || e.metaKey;
+            if (mod && e.key.toLowerCase() === 's') {
+                e.preventDefault();
+                Save.run();
+                return;
+            }
+            if (mod && e.key.toLowerCase() === 'z') {
+                e.preventDefault();
+                if (e.shiftKey) Doc.redo(); else Doc.undo();
+                return;
+            }
+            if (mod && e.key.toLowerCase() === 'y') {
+                e.preventDefault();
+                Doc.redo();
+                return;
+            }
+            if (mod && e.key.toLowerCase() === 'a') {
+                e.preventDefault();
+                Canvas.Actions.selectAll();
+                return;
+            }
+            if (mod) return;
+
+            switch (e.key) {
+                case 'Delete':
+                case 'Backspace':
+                    e.preventDefault();
+                    Canvas.Actions.deleteSelection();
+                    break;
+                case 'Escape':
+                    if (!Canvas.Interact.cancel()) Select.clear();
+                    break;
+                case 'Enter':
+                    var sel = Select.nodes();
+                    if (sel.length === 1) {
+                        e.preventDefault();
+                        Canvas.Edit.open(sel[0]);
+                    }
+                    break;
+                case 'ArrowUp': e.preventDefault(); Canvas.Actions.nudge(0, -1, e.shiftKey); break;
+                case 'ArrowDown': e.preventDefault(); Canvas.Actions.nudge(0, 1, e.shiftKey); break;
+                case 'ArrowLeft': e.preventDefault(); Canvas.Actions.nudge(-1, 0, e.shiftKey); break;
+                case 'ArrowRight': e.preventDefault(); Canvas.Actions.nudge(1, 0, e.shiftKey); break;
+                case 't': Canvas.Edit.open(Canvas.Actions.addText().id); break;
+                case 'f': Canvas.Actions.addFile(); break;
+                case 'l': Canvas.Actions.addLink(); break;
+                case 'g': Canvas.Actions.addGroup(); break;
+                case '9': View.fit(Doc.nodes()); break;
+                case '0': View.resetZoom(); break;
+                case '+':
+                case '=': View.zoomBy(1.2); break;
+                case '-': View.zoomBy(1 / 1.2); break;
+            }
+        });
+    }
+
+    // --- boot ---
+
+    Doc.init(data.doc, data.hash);
+    Nodes.seed(data.rendered, Doc.get());
+    Nodes.init(document.getElementById('canvas-nodes'), document.getElementById('canvas-groups'));
+    Edges.init(document.getElementById('canvas-edges'));
+    View.init(surface, world);
+    Canvas.Interact.init(surface, marquee);
+    Save.init(data.postUrl, data.name);
+
+    Doc.onChange(refresh);
+    Select.onChange(function () {
+        Nodes.syncSelection();
+        Edges.syncSelection();
+        updateToolbar();
+    });
+    View.onChange(updateZoom);
+    Save.onState(function (state, message) { setStatus(message); });
+
+    wireToolbar();
+    wireKeys();
+
+    refresh();
+    View.fit(Doc.nodes());
+    updateZoom();
+    surface.focus();
+})();

assets/canvas/save.js

@@ -0,0 +1,125 @@
+// save.js — writing the canvas back.
+//
+// The whole document goes up in one request: a canvas is a single JSON object
+// whose edges reference node ids, so a partial patch would have to reason about
+// cross-references the server would then have to re-validate anyway.
+//
+// Two server rejections are worth handling rather than dumping on the user:
+// a 409 (someone else changed the file) and the empty-canvas guard (which asks
+// for explicit confirmation before letting a save blank a populated canvas).
+window.Canvas = window.Canvas || {};
+
+Canvas.Save = (function () {
+    var Doc = Canvas.Doc;
+
+    var action = '';
+    var saving = false;
+    var listeners = [];
+
+    function emit(state, message) {
+        for (var i = 0; i < listeners.length; i++) listeners[i](state, message);
+    }
+
+    function post(url) {
+        return fetch(url, {
+            method: 'POST',
+            credentials: 'same-origin',
+            headers: {
+                'Content-Type': 'application/json',
+                'X-Canvas-Version': Doc.version()
+            },
+            body: JSON.stringify(Doc.get())
+        });
+    }
+
+    function run(force) {
+        if (saving) return Promise.resolve(false);
+        if (!Doc.isDirty() && !force) {
+            emit('clean', 'no changes');
+            return Promise.resolve(true);
+        }
+        saving = true;
+        emit('saving', 'saving…');
+
+        var url = action + (force ? '&empty=1' : '');
+        return post(url).then(function (res) {
+            if (res.status === 204) {
+                Doc.markSaved(res.headers.get('X-Canvas-Version') || '');
+                emit('clean', 'saved');
+                return true;
+            }
+            return res.text().then(function (msg) {
+                if (res.status === 409) {
+                    conflict(msg);
+                } else if (res.status === 400 && msg.indexOf('empty canvas') !== -1) {
+                    confirmEmpty(msg);
+                } else {
+                    emit('error', msg || ('save failed (' + res.status + ')'));
+                    alert(msg || ('Save failed (' + res.status + ')'));
+                }
+                return false;
+            });
+        }).catch(function () {
+            emit('error', 'network error');
+            alert('Could not reach the server — your changes are still here, try again.');
+            return false;
+        }).finally(function () {
+            saving = false;
+        });
+    }
+
+    // conflict: the file changed underneath us. Overwriting silently would
+    // discard whatever the other writer did, so the choice is the user's — and
+    // reloading would discard *their* work, so that is spelled out too.
+    function conflict(msg) {
+        emit('error', 'conflict');
+        openModal({
+            title: 'Canvas changed on disk',
+            body: msg + '\n\nReload to take the version on disk (your unsaved changes here are lost), ' +
+                'or keep editing and save again to overwrite it.',
+            confirm: {
+                label: 'RELOAD',
+                danger: true,
+                onConfirm: function () {
+                    closeModal();
+                    window.location.reload();
+                }
+            },
+            cancel: { label: 'KEEP EDITING', autofocus: true }
+        });
+    }
+
+    function confirmEmpty(msg) {
+        emit('error', 'refused');
+        openModal({
+            title: 'Save an empty canvas?',
+            body: msg + '\n\nThis removes every node from the file.',
+            confirm: {
+                label: 'EMPTY IT',
+                danger: true,
+                onConfirm: function () {
+                    closeModal();
+                    run(true);
+                }
+            }
+        });
+    }
+
+    return {
+        init: function (postURL, name) {
+            action = postURL + '?canvas=' + encodeURIComponent(name);
+            // Unsaved work must not vanish on a stray Back or tab close. The
+            // browser shows its own generic wording; the return value is only a
+            // signal that there is something to lose.
+            window.addEventListener('beforeunload', function (e) {
+                if (!Doc.isDirty()) return;
+                e.preventDefault();
+                e.returnValue = '';
+            });
+        },
+
+        run: function () { return run(false); },
+        isSaving: function () { return saving; },
+        onState: function (fn) { listeners.push(fn); }
+    };
+})();

assets/canvas/select.js

@@ -0,0 +1,77 @@
+// select.js — which nodes and edges are selected.
+//
+// Kept apart from the document so selection never lands in the undo stack or
+// on disk: undoing an edit should restore geometry, not re-select whatever
+// happened to be highlighted at the time.
+window.Canvas = window.Canvas || {};
+
+Canvas.Select = (function () {
+    var nodes = {};
+    var edges = {};
+    var listeners = [];
+
+    function emit() {
+        for (var i = 0; i < listeners.length; i++) listeners[i]();
+    }
+
+    function keys(obj) { return Object.keys(obj); }
+
+    return {
+        nodes: function () { return keys(nodes); },
+        edges: function () { return keys(edges); },
+        hasNode: function (id) { return !!nodes[id]; },
+        hasEdge: function (id) { return !!edges[id]; },
+        isEmpty: function () { return !keys(nodes).length && !keys(edges).length; },
+        count: function () { return keys(nodes).length + keys(edges).length; },
+
+        set: function (nodeIds, edgeIds) {
+            nodes = {};
+            edges = {};
+            (nodeIds || []).forEach(function (id) { nodes[id] = true; });
+            (edgeIds || []).forEach(function (id) { edges[id] = true; });
+            emit();
+        },
+
+        addNode: function (id) {
+            if (nodes[id]) return;
+            nodes[id] = true;
+            emit();
+        },
+
+        toggleNode: function (id) {
+            if (nodes[id]) delete nodes[id]; else nodes[id] = true;
+            emit();
+        },
+
+        toggleEdge: function (id) {
+            if (edges[id]) delete edges[id]; else edges[id] = true;
+            emit();
+        },
+
+        clear: function () {
+            if (!keys(nodes).length && !keys(edges).length) return;
+            nodes = {};
+            edges = {};
+            emit();
+        },
+
+        // prune drops ids that no longer exist. Called after undo/redo, where
+        // the document can lose nodes the selection still refers to.
+        prune: function (doc) {
+            var changed = false;
+            var live = {};
+            doc.nodes.forEach(function (n) { live[n.id] = true; });
+            keys(nodes).forEach(function (id) {
+                if (!live[id]) { delete nodes[id]; changed = true; }
+            });
+            var liveEdges = {};
+            doc.edges.forEach(function (e) { liveEdges[e.id] = true; });
+            keys(edges).forEach(function (id) {
+                if (!liveEdges[id]) { delete edges[id]; changed = true; }
+            });
+            if (changed) emit();
+        },
+
+        onChange: function (fn) { listeners.push(fn); }
+    };
+})();

assets/canvas/view.js

@@ -0,0 +1,147 @@
+// view.js — pan and zoom.
+//
+// The whole scene lives in one transformed <div>, so panning and zooming cost a
+// single CSS transform: no relayout, no re-render of node content, nothing that
+// touches the DOM per node. That is what keeps a few hundred nodes usable on
+// the mobile/VPN path.
+//
+// The dot grid is painted on the (untransformed) surface and its size/offset
+// follow the transform, which keeps it crisp at every zoom level instead of
+// scaling a bitmap.
+window.Canvas = window.Canvas || {};
+
+Canvas.View = (function () {
+    var MIN_SCALE = 0.05;
+    var MAX_SCALE = 4;
+    var GRID = 20;
+
+    var surface = null;
+    var world = null;
+    var tx = 0, ty = 0, scale = 1;
+    var listeners = [];
+
+    function apply() {
+        world.style.transform = 'translate(' + tx + 'px,' + ty + 'px) scale(' + scale + ')';
+        var step = GRID * scale;
+        surface.style.backgroundSize = step + 'px ' + step + 'px';
+        surface.style.backgroundPosition = tx + 'px ' + ty + 'px';
+        // Below a few pixels apart the dots stop reading as a grid and start
+        // reading as noise, so zooming far out drops them entirely.
+        surface.classList.toggle('is-grid-hidden', step < 6);
+        for (var i = 0; i < listeners.length; i++) listeners[i]();
+    }
+
+    function clampScale(s) {
+        return Math.max(MIN_SCALE, Math.min(MAX_SCALE, s));
+    }
+
+    // zoomAt scales about a screen point, so the world coordinate under the
+    // cursor stays put — the behaviour that makes wheel-zoom feel anchored
+    // rather than lurching toward the origin.
+    function zoomAt(clientX, clientY, factor) {
+        var next = clampScale(scale * factor);
+        if (next === scale) return;
+        var r = surface.getBoundingClientRect();
+        var px = clientX - r.left;
+        var py = clientY - r.top;
+        var ratio = next / scale;
+        tx = px - (px - tx) * ratio;
+        ty = py - (py - ty) * ratio;
+        scale = next;
+        apply();
+    }
+
+    function bounds(nodes) {
+        if (!nodes.length) return null;
+        var minX = Infinity, minY = Infinity, maxX = -Infinity, maxY = -Infinity;
+        nodes.forEach(function (n) {
+            minX = Math.min(minX, n.x);
+            minY = Math.min(minY, n.y);
+            maxX = Math.max(maxX, n.x + n.width);
+            maxY = Math.max(maxY, n.y + n.height);
+        });
+        return { x: minX, y: minY, width: maxX - minX, height: maxY - minY };
+    }
+
+    return {
+        GRID: GRID,
+
+        init: function (surfaceEl, worldEl) {
+            surface = surfaceEl;
+            world = worldEl;
+            apply();
+        },
+
+        get: function () { return { x: tx, y: ty, scale: scale }; },
+        scale: function () { return scale; },
+
+        toWorld: function (clientX, clientY) {
+            var r = surface.getBoundingClientRect();
+            return {
+                x: (clientX - r.left - tx) / scale,
+                y: (clientY - r.top - ty) / scale
+            };
+        },
+
+        toScreen: function (x, y) {
+            var r = surface.getBoundingClientRect();
+            return { x: x * scale + tx + r.left, y: y * scale + ty + r.top };
+        },
+
+        pan: function (dx, dy) {
+            tx += dx;
+            ty += dy;
+            apply();
+        },
+
+        zoomAt: zoomAt,
+
+        // zoomBy scales about the viewport centre, for the toolbar buttons and
+        // the +/- shortcuts where there is no cursor to anchor to.
+        zoomBy: function (factor) {
+            var r = surface.getBoundingClientRect();
+            zoomAt(r.left + r.width / 2, r.top + r.height / 2, factor);
+        },
+
+        resetZoom: function () {
+            var r = surface.getBoundingClientRect();
+            zoomAt(r.left + r.width / 2, r.top + r.height / 2, 1 / scale);
+        },
+
+        // fit frames the whole document with a margin, never zooming past 1:1 —
+        // a canvas with three small nodes should not open comically magnified.
+        fit: function (nodes) {
+            var b = bounds(nodes);
+            var r = surface.getBoundingClientRect();
+            if (!b || !r.width || !r.height) {
+                tx = 0; ty = 0; scale = 1;
+                apply();
+                return;
+            }
+            var pad = 60;
+            var s = clampScale(Math.min(
+                (r.width - pad * 2) / Math.max(b.width, 1),
+                (r.height - pad * 2) / Math.max(b.height, 1),
+                1
+            ));
+            scale = s;
+            tx = r.width / 2 - (b.x + b.width / 2) * s;
+            ty = r.height / 2 - (b.y + b.height / 2) * s;
+            apply();
+        },
+
+        // centreOfViewport is where a newly added node goes: wherever the user
+        // is currently looking.
+        centreOfViewport: function () {
+            var r = surface.getBoundingClientRect();
+            return {
+                x: (r.width / 2 - tx) / scale,
+                y: (r.height / 2 - ty) / scale
+            };
+        },
+
+        bounds: bounds,
+        onChange: function (fn) { listeners.push(fn); },
+        refresh: apply
+    };
+})();

assets/diary/calendar.html

@@ -24,4 +24,4 @@
   </table>
   {{end}}
 </div>
-<script src="{{asset "diary/calendar.js"}}"></script>
+<script src="/_/diary/calendar.js"></script>

assets/diary/content.html

@@ -10,8 +10,4 @@
   {{end}}
 </div>
 {{end}}
-{{if or .Events .Weight}}<div class="diary-day-cal muted">
-{{if .Events}}<p>{{.Events}}</p>{{end}}
-{{if .Weight}}<p>{{.Weight}}</p>{{end}}
-</div>{{end}}
 {{end}}

assets/editor/main.html

@@ -78,10 +78,10 @@
     <div id="editor" class="editor-cm"></div>
     <textarea name="content" id="editor-content" hidden>{{.RawContent}}</textarea>
 </form>
-<script src="{{asset "editor/vendor/codemirror.bundle.js"}}"></script>
+<script src="/_/editor/vendor/codemirror.bundle.js?v={{editorBundleVersion}}"></script>
-<script src="{{asset "editor/tables.js"}}"></script>
+<script src="/_/editor/tables.js"></script>
-<script src="{{asset "editor/dates.js"}}"></script>
+<script src="/_/editor/dates.js"></script>
-<script src="{{asset "editor/movie.js"}}"></script>
+<script src="/_/editor/movie.js"></script>
-<script src="{{asset "editor/wikicomplete.js"}}"></script>
+<script src="/_/editor/wikicomplete.js"></script>
-<script src="{{asset "editor/main.js"}}"></script>
+<script src="/_/editor/main.js"></script>
 {{end}}

assets/editor/tables.js

@@ -6,34 +6,22 @@ window.EditorTables = (function () {
         return s;
     }
 
-    var segmenter = new Intl.Segmenter(undefined, { granularity: 'grapheme' });
-
-    // Graphemes rendered two columns wide: emoji-presentation characters, anything
-    // forced to emoji presentation via VS16, and East Asian wide/fullwidth ranges.
-    var WIDE = /\p{Emoji_Presentation}|️|[ᄀ-ᅟ⺀-〾ぁ-㏿㐀-䶿一-鿿ꀀ-꓏가-힣豈-﫿︰-﹏＀-｠￠-￦]/u;
-    var ZERO = /^[\p{Mn}\p{Me}\p{Cf}]+$/u;
-
-    function displayWidth(s) {
-        var w = 0;
-        Array.from(segmenter.segment(s), function (seg) {
-            var g = seg.segment;
-            if (!ZERO.test(g)) w += WIDE.test(g) ? 2 : 1;
-        });
-        return w;
-    }
-
     function padLeft(s, w) {
-        return repeat(' ', w - displayWidth(s)) + s;
+        while (s.length < w) s = ' ' + s;
+        return s;
     }
 
     function padRight(s, w) {
-        return s + repeat(' ', w - displayWidth(s));
+        while (s.length < w) s += ' ';
+        return s;
     }
 
     function padCenter(s, w) {
-        var total = w - displayWidth(s);
+        while (s.length < w) {
-        var left = Math.floor(total / 2);
+            s = s + ' ';
-        return repeat(' ', left) + s + repeat(' ', total - left);
+            if (s.length < w) s = ' ' + s;
+        }
+        return s;
     }
 
     function parseTableRow(line) {
@@ -113,8 +101,7 @@ window.EditorTables = (function () {
             var max = 3;
             for (var r = 0; r < rows.length; r++) {
                 if (r === sepIndex) continue;
-                var len = displayWidth(rows[r][c]);
+                if (rows[r][c].length > max) max = rows[r][c].length;
-                if (len > max) max = len;
             }
             widths.push(max);
         }

assets/fitness/fitness.js

@@ -1,74 +1,10 @@
-// Fitness dashboard range dropdowns and "absolute" checkboxes: changing one
+// Fitness dashboard range dropdowns: changing one reloads the page with that
-// reloads the page with that chart's query parameter updated. Plain GET
+// chart's query parameter updated. Plain GET navigation — each range is a
-// navigation — each view is distinct and bookmarkable, so no
+// distinct, bookmarkable view, so no postReplace/history handling is needed.
-// postReplace/history handling is needed.
 document.addEventListener('change', function (e) {
-    var url = new URL(window.location.href);
     var sel = e.target.closest('[data-fitness-range]');
-    var abs = e.target.closest('[data-fitness-absolute]');
+    if (!sel) return;
-    if (sel) {
+    var url = new URL(window.location.href);
-        url.searchParams.set(sel.dataset.fitnessRange, sel.value);
+    url.searchParams.set(sel.dataset.fitnessRange, sel.value);
-    } else if (abs) {
-        if (abs.checked) url.searchParams.set(abs.dataset.fitnessAbsolute, '1');
-        else url.searchParams.delete(abs.dataset.fitnessAbsolute);
-    } else {
-        return;
-    }
     window.location.href = url.toString();
 });
-
-// Hover tooltip: the pointer snaps to the data point nearest in time. Dots
-// are sorted by x, so a binary search finds it; the tooltip sits above the
-// point and is clamped to the chart panel.
-function fitnessNearest(dots, x) {
-    var lo = 0, hi = dots.length - 1;
-    while (lo < hi) {
-        var mid = (lo + hi) >> 1;
-        if (dots[mid].cx.baseVal.value < x) lo = mid + 1; else hi = mid;
-    }
-    if (lo > 0 && x - dots[lo - 1].cx.baseVal.value < dots[lo].cx.baseVal.value - x) lo--;
-    return dots[lo];
-}
-
-function fitnessHide(svg) {
-    var chart = svg.closest('.fitness-chart');
-    svg.classList.remove('is-hover');
-    chart.querySelector('.fitness-tip').hidden = true;
-}
-
-document.addEventListener('pointermove', function (e) {
-    var svg = e.target.closest && e.target.closest('.fitness-svg');
-    document.querySelectorAll('.fitness-svg').forEach(function (other) {
-        if (other !== svg) fitnessHide(other);
-    });
-    if (!svg) return;
-    var dots = svg.querySelectorAll('.chart-dot');
-    if (!dots.length) return;
-    var ctm = svg.getScreenCTM();
-    if (!ctm) return;
-    var pt = new DOMPoint(e.clientX, e.clientY).matrixTransform(ctm.inverse());
-    var dot = fitnessNearest(dots, pt.x);
-    var cx = dot.cx.baseVal.value, cy = dot.cy.baseVal.value;
-
-    var cursor = svg.querySelector('.chart-cursor');
-    cursor.setAttribute('x1', cx);
-    cursor.setAttribute('x2', cx);
-    var focus = svg.querySelector('.chart-focus');
-    focus.setAttribute('cx', cx);
-    focus.setAttribute('cy', cy);
-    svg.classList.add('is-hover');
-
-    var chart = svg.closest('.fitness-chart');
-    var tip = chart.querySelector('.fitness-tip');
-    tip.firstElementChild.textContent = dot.dataset.date;
-    tip.lastElementChild.textContent = dot.dataset.value;
-    tip.hidden = false;
-    var box = chart.getBoundingClientRect();
-    var at = new DOMPoint(cx, cy).matrixTransform(ctm);
-    var left = at.x - box.left - tip.offsetWidth / 2;
-    left = Math.max(0, Math.min(left, box.width - tip.offsetWidth));
-    var top = at.y - box.top - tip.offsetHeight - 10;
-    if (top < 0) top = at.y - box.top + 10;
-    tip.style.left = left + 'px';
-    tip.style.top = top + 'px';
-});

assets/fitness/main.html

@@ -2,23 +2,19 @@
 <section class="fitness-chart panel">
     <div class="fitness-chart-header row space-between">
         <span class="caption">{{.Title}}</span>
-        <div class="row fitness-controls">
+        <select class="input fitness-range" data-fitness-range="{{.Param}}" aria-label="{{.Title}} time range">
-            <label class="fitness-absolute"><input type="checkbox" data-fitness-absolute="{{.Param}}-absolute"{{if .Absolute}} checked{{end}}> Absolute</label>
+            {{range .Options}}<option value="{{.Value}}"{{if .Selected}} selected{{end}}>{{.Label}}</option>{{end}}
-            <select class="input fitness-range" data-fitness-range="{{.Param}}" aria-label="{{.Title}} time range">
+        </select>
-                {{range .Options}}<option value="{{.Value}}"{{if .Selected}} selected{{end}}>{{.Label}}</option>{{end}}
-            </select>
-        </div>
     </div>
     {{if .Empty}}
     <p class="fitness-empty is-empty">No data in this range.</p>
     {{else}}
-    <svg class="fitness-svg{{if .Dense}} is-dense{{end}}" viewBox="0 0 {{.ViewW}} {{.ViewH}}" role="img" aria-label="{{.Title}}">
+    <svg class="fitness-svg" viewBox="0 0 {{.ViewW}} {{.ViewH}}" role="img" aria-label="{{.Title}}">
         {{range .YTicks}}
         <line class="chart-grid" x1="{{$.PlotX}}" y1="{{.Pos}}" x2="{{$.PlotR}}" y2="{{.Pos}}"/>
         <text class="chart-label" x="{{$.YLabelX}}" y="{{.Pos}}" text-anchor="end" dominant-baseline="middle">{{.Label}}</text>
         {{end}}
         {{range .XTicks}}
-        <line class="chart-grid" x1="{{.Pos}}" y1="{{$.PlotY}}" x2="{{.Pos}}" y2="{{$.PlotB}}"/>
         <text class="chart-label" x="{{.Pos}}" y="{{$.XLabelY}}" text-anchor="{{.Anchor}}">{{.Label}}</text>
         {{end}}
         <line class="chart-axis" x1="{{.PlotX}}" y1="{{.PlotY}}" x2="{{.PlotX}}" y2="{{.PlotB}}"/>
@@ -27,16 +23,13 @@
         <polyline class="chart-line" points="{{.}}"/>
         {{end}}
         {{range .Dots}}
-        <circle class="chart-dot" cx="{{.X}}" cy="{{.Y}}" r="2.5" data-date="{{.Date}}" data-value="{{.Value}}"/>
+        <circle class="chart-dot" cx="{{.X}}" cy="{{.Y}}" r="2.5"><title>{{.Title}}</title></circle>
         {{end}}
         {{if .Goal}}
         <line class="chart-goal" x1="{{.PlotX}}" y1="{{.Goal.Y}}" x2="{{.PlotR}}" y2="{{.Goal.Y}}"/>
         <text class="chart-goal-label" x="{{.PlotR}}" y="{{.Goal.LabelY}}" text-anchor="end">{{.Goal.Label}}</text>
         {{end}}
-        <line class="chart-cursor" x1="0" y1="{{.PlotY}}" x2="0" y2="{{.PlotB}}"/>
-        <circle class="chart-focus" r="4"/>
     </svg>
-    <div class="fitness-tip" hidden><strong></strong><span></span></div>
     {{end}}
 </section>
 {{end}}
@@ -47,4 +40,4 @@
     {{range .Charts}}{{template "fitnessChart" .}}{{end}}
 {{end}}
 </div>
-<script src="{{asset "fitness/fitness.js"}}"></script>
+<script src="/_/fitness/fitness.js"></script>

assets/global-shortcuts.js

@@ -16,12 +16,6 @@
                 e.preventDefault();
                 if (window.location.pathname !== '/' && typeof movePage === 'function') movePage();
                 break;
-            case 'H':
-                var maint = document.querySelector('[data-action="maint-menu"]');
-                if (!maint) return;
-                e.preventDefault();
-                maint.click();
-                break;
             case 'F':
                 var input = document.querySelector('.search-input');
                 if (!input) return;
@@ -64,14 +58,12 @@ document.addEventListener('keydown', function (e) {
 });
 
 document.addEventListener('DOMContentLoaded', function () {
-  ['actions-menu', 'maint-menu'].forEach(function (action) {
+  var trigger = document.querySelector('[data-action="actions-menu"]');
-    var trigger = document.querySelector('[data-action="' + action + '"]');
+  if (!trigger) return;
-    if (!trigger) return;
+  wireDropdown(trigger);
-    wireDropdown(trigger);
+  var menu = trigger.parentElement.querySelector('.dropdown-menu');
-    var menu = trigger.parentElement.querySelector('.dropdown-menu');
+  if (!menu) return;
-    if (!menu) return;
+  trigger.addEventListener('click', function () {
-    trigger.addEventListener('click', function () {
+    trigger.setAttribute('aria-expanded', menu.classList.contains('is-open') ? true : false);
-      trigger.setAttribute('aria-expanded', menu.classList.contains('is-open') ? true : false);
-    });
   });
 });

assets/icons/canvas.svg

@@ -1,4 +1,4 @@
 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="1em" height="1em"
-     fill="none" stroke="currentColor" stroke-width="1.5" stroke-linejoin="miter" stroke-linecap="square">
+     fill="none" stroke="currentColor" stroke-width="1.5" stroke-linejoin="miter" shape-rendering="crispEdges">
-  <path d="M8 3v10M3 8h10"/>
+  <path d="M1 2h6v5H1zM9 9h6v5H9zM4 7v4h5"/>
 </svg>

assets/icons/delete.svg

@@ -1,4 +0,0 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="1em" height="1em"
-     fill="none" stroke="currentColor" stroke-width="1.5" stroke-linejoin="miter" stroke-linecap="square">
-  <path d="M2 4h12M6 4V2h4v2M4 4l1 10h6l1-10M7 7v4M9 7v4"/>
-</svg>

assets/icons/edit.svg

@@ -1,4 +0,0 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="1em" height="1em"
-     fill="none" stroke="currentColor" stroke-width="1.5" stroke-linejoin="miter" stroke-linecap="square">
-  <path d="M11 2l3 3-8 8H3v-3zM9 4l3 3"/>
-</svg>

assets/icons/maintenance.svg

@@ -1,4 +0,0 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="1em" height="1em"
-     fill="none" stroke="currentColor" stroke-width="1.5" stroke-linejoin="miter" stroke-linecap="square">
-  <path d="M2 3h12v11H2zM2 6h12M5 1v2M11 1v2M5 10l2 2 4-4"/>
-</svg>

assets/icons/move.svg

@@ -1,4 +0,0 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="1em" height="1em"
-     fill="none" stroke="currentColor" stroke-width="1.5" stroke-linejoin="miter" stroke-linecap="square">
-  <path d="M2 8h8M7 5l3 3-3 3M13 2v12"/>
-</svg>

assets/icons/rebuild.svg

@@ -1,4 +0,0 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="1em" height="1em"
-     fill="none" stroke="currentColor" stroke-width="1.5" stroke-linejoin="miter" stroke-linecap="square">
-  <path d="M13 8a5 5 0 1 1-1.5-3.5M12 1v4H8"/>
-</svg>

assets/icons/reveal.svg

@@ -1,4 +0,0 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" width="1em" height="1em"
-     fill="none" stroke="currentColor" stroke-width="1.5" stroke-linejoin="miter" stroke-linecap="square">
-  <path d="M1 14V3h5l1 2h8v9zM8 12V8M6 10l2-2 2 2"/>
-</svg>

assets/layout.html

@@ -4,19 +4,19 @@
         <meta charset="UTF-8" />
         <meta name="viewport" content="width=device-width, initial-scale=1, interactive-widget=resizes-content" />
         <title>{{.Title}}</title>
-        <link rel="icon" href="{{asset "favicon.ico"}}" />
+        <link rel="icon" href="/_/favicon.ico" />
         <link rel="preload" href="/_/fonts/IosevkaEtoile.woff2" as="font" type="font/woff2" crossorigin />
         <link rel="preload" href="/_/fonts/IosevkaSlab.woff2" as="font" type="font/woff2" crossorigin />
-        <link rel="stylesheet" href="{{asset "style.css"}}" />
+        <link rel="stylesheet" href="/_/style.css" />
-        <script src="{{asset "modal.js"}}"></script>
+        <script src="/_/modal.js"></script>
-        <script src="{{asset "global-shortcuts.js"}}"></script>
+        <script src="/_/global-shortcuts.js"></script>
-        <script src="{{asset "history-nav.js"}}"></script>
+        <script src="/_/history-nav.js"></script>
-        <script src="{{asset "scroll-sync.js"}}" defer></script>
+        <script src="/_/scroll-sync.js" defer></script>
-        <script src="{{asset "search-suggest.js"}}" defer></script>
+        <script src="/_/search-suggest.js" defer></script>
-        <script src="{{asset "tree-picker.js"}}"></script>
+        <script src="/_/tree-picker.js"></script>
-        <script src="{{asset "companion.js"}}" defer></script>
+        <script src="/_/companion.js" defer></script>
-        {{if not .EditMode}}<script src="{{asset "overlay.js"}}" defer></script>
+        {{if .ShowPageChrome}}<script src="/_/overlay.js" defer></script>
-        <script src="{{asset "tree-sidebar.js"}}" defer></script>{{end}}
+        <script src="/_/tree-sidebar.js" defer></script>{{end}}
         {{block "headScripts" .}}{{end}}
     </head>
     <body>
@@ -24,14 +24,13 @@
             <nav class="breadcrumb row">
                 <a href="/" tabindex="-1" title="Home"><svg class="logo" viewBox="0 0 26.052269 26.052269" xmlns="http://www.w3.org/2000/svg"><g fill="none" stroke="currentColor" stroke-linejoin="miter" transform="matrix(0.05463483,8.1519706e-6,-8.1519706e-6,0.05463483,-64.560546,-24.6949)"><rect x="1188.537" y="457.92056" width="461.87488" height="462.15189" stroke-width="20.2288"/><path d="m1348.9955 456.59572.046 309.36839" stroke-width="19.6849"/><path d="m1200.3996 765.80237 441.8362-.0659" stroke-width="19.6849"/><path d="m1648.2897 620.244-299.2012.0446" stroke-width="20.5676"/><path d="m1491.6148 909.24806-.021-136.93117" stroke-width="19.6849"/><rect x="1191.6504" y="461.66092" width="457.09634" height="457.09634" stroke-width="19.6761"/></g></svg><span class="app-name"> datascape</span></a>
             </nav>
-            {{if not .EditMode}}
+            {{if .ShowPageChrome}}
             <form class="search-form" action="/" method="get">
                 <input class="input search-input" type="search" name="q" value="{{block "searchQuery" .}}{{end}}" placeholder="Search…" title="Search (F)" autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false" />
             </form>
             {{end}}
             <div class="header-actions row">
-                {{if .EditMode}}{{block "headerActions" .}}{{end}}{{else}}
+                {{if not .ShowPageChrome}}{{block "headerActions" .}}{{end}}{{else}}
-                {{maintenanceWidget}}
                 <span class="dropdown actions">
                     <button type="button" class="btn actions-toggle" data-action="actions-menu" aria-haspopup="true" aria-expanded="false" title="Actions">ACTIONS</button>
                     <div class="dropdown-menu align-right actions-menu">
@@ -43,23 +42,8 @@
             </div>
         </header>
         <div class="shell">
-            {{if not .EditMode}}<aside class="tree-sidebar col">
+            {{if .ShowPageChrome}}<aside class="tree-sidebar col">
                 <div class="tree-scroll"></div>
-                <script>
-                    // Paint the previous page's tree before first render so the rail
-                    // doesn't flash empty; tree-sidebar.js swaps in the live tree.
-                    (function () {
-                        try {
-                            var s = JSON.parse(sessionStorage.getItem("tree-snapshot"));
-                            if (!s) return;
-                            var el = document.currentScript.previousElementSibling;
-                            el.innerHTML = s.html;
-                            var a = el.querySelector('a.tree-name[href="' + CSS.escape(location.pathname.replace(/\/*$/, "/")) + '"]');
-                            if (a) a.parentNode.classList.add("is-active");
-                            el.scrollTop = s.top;
-                        } catch (e) {}
-                    })();
-                </script>
             </aside>{{end}}
             <div class="center">
                 <main>
@@ -74,7 +58,7 @@
                     </span>
                 </footer>
             </div>
-            {{if not .EditMode}}{{block "aside" .}}{{end}}{{end}}
+            {{if .ShowPageChrome}}{{block "aside" .}}{{end}}{{end}}
         </div>
         {{block "extras" .}}{{end}}
     </body>

assets/page/canvas-actions.js

@@ -0,0 +1,43 @@
+// canvas-actions.js — creating a canvas from a normal page.
+//
+// The canvas view itself owns everything else (rename, delete, editing); this
+// only covers the one action that has to start from the page, since a folder
+// with no canvases has no canvas view to reach.
+//
+// Reuses openModal and postReplace from page/actions.js, which the page
+// template loads first.
+
+// validCanvasName mirrors canvasNameRe in canvas.go. Checking here only buys a
+// better error message — the server rejects the same set regardless.
+function validCanvasName(name) {
+    if (!name || name.length > 100) return false;
+    if (name.charAt(0) === '.') return false;
+    return !/[\/\\]/.test(name);
+}
+
+function newCanvas() {
+    var input = document.createElement('input');
+    input.type = 'text';
+    input.className = 'input';
+    input.placeholder = 'Canvas name';
+
+    openModal({
+        title: 'New canvas',
+        body: input,
+        confirm: {
+            label: 'CREATE',
+            onConfirm: function () {
+                var name = input.value.trim();
+                if (!validCanvasName(name)) {
+                    alert('A canvas name cannot be empty, start with a dot, or contain a slash.');
+                    return;
+                }
+                closeModal();
+                var base = window.location.pathname;
+                if (base.slice(-1) !== '/') base += '/';
+                var target = base + '?canvas=' + encodeURIComponent(name);
+                postReplace(target + '&create=1', null, target);
+            }
+        }
+    });
+}

assets/page/main.html

@@ -1,25 +1,34 @@
-{{define "headScripts"}}<script src="{{asset "page/actions.js"}}"></script>{{end}}
+{{define "headScripts"}}<script src="/_/page/actions.js"></script>
+<script src="/_/page/canvas-actions.js"></script>{{end}}
 
 {{define "headerActions"}}{{if .CanEdit}}
-<button class="btn btn-block" onclick="newPage()" title="New page (N)"><span class="btn-icon">{{icon "new"}}</span><span class="btn-label">NEW</span></button>
+<button class="btn btn-block" onclick="newPage()" title="New page (N)">NEW</button>
-<button class="btn btn-block" data-companion-reveal hidden title="Reveal in file manager"><span class="btn-icon">{{icon "reveal"}}</span><span class="btn-label">REVEAL</span></button>
+<button class="btn btn-block" data-companion-reveal hidden title="Reveal in file manager">REVEAL</button>
 {{if not .IsRoot}}
-<button class="btn btn-block" onclick="movePage()" title="Move page (M)"><span class="btn-icon">{{icon "move"}}</span><span class="btn-label">MOVE</span></button>
+<button class="btn btn-block" onclick="movePage()" title="Move page (M)">MOVE</button>
-<button class="btn btn-block danger" onclick="deletePage()" title="Delete page"><span class="btn-icon">{{icon "delete"}}</span><span class="btn-label">DELETE</span></button>
+<button class="btn btn-block danger" onclick="deletePage()" title="Delete page">DELETE</button>
 {{end}}
-<a class="btn btn-block" href="?edit" title="Edit page (E)"><span class="btn-icon">{{icon "edit"}}</span><span class="btn-label">EDIT</span></a>
+<a class="btn btn-block" href="?edit" title="Edit page (E)">EDIT</a>
+<button class="btn btn-block" onclick="newCanvas()" title="New canvas">NEW CANVAS</button>
 {{end}}{{end}}
 
 {{define "content"}}
+{{/* Canvases in this folder are alternative views of the same page, so they
+     read as a tab strip above the content rather than as rows in the file
+     listing (listEntries filters them out for exactly this reason). */}}
+{{if .Canvases}}
+<nav class="canvas-tabs row" aria-label="Page views">
+    <span class="canvas-tab is-active">PAGE</span>
+    {{range .Canvases}}<a class="canvas-tab" href="{{.URL}}">{{.Name}}</a>{{end}}
+    {{if .CanEdit}}<button type="button" class="canvas-tab canvas-tab-add" onclick="newCanvas()" title="New canvas">+</button>{{end}}
+</nav>
+{{end}}
 {{if .Content}}
 <div class="content">{{.Content}}</div>
 {{end}}
 {{if .SpecialContent}}
 <div class="content">{{.SpecialContent}}</div>
 {{end}}
-{{if not (or .Content .SpecialContent)}}
-<p class="empty">{{if .Entries}}No page{{else}}Empty folder{{end}} — <a href="?edit">[CREATE]</a></p>
-{{end}}
 {{if .Entries}}
 <h2 id="files">Files <button class="btn btn-small" data-companion-reveal hidden title="Open folder in file manager">open</button>{{if .CanEdit}} <button class="btn btn-small" id="view-settings-btn" onclick="openViewSettings()" title="View &amp; sorting" data-view="{{.View}}" data-sort="{{.Sort}}" data-order="{{.Order}}">view</button>{{end}}</h2>
 {{if eq .View "thumbnail"}}
@@ -44,17 +53,21 @@
     </tbody>
 </table>
 {{end}}
-{{if .CanEdit}}<script src="{{asset "page/view-settings.js"}}"></script>{{end}}
+{{if .CanEdit}}<script src="/_/page/view-settings.js"></script>{{end}}
+{{else if not .Content}}
+{{if not .SpecialContent}}
+<p class="empty">Empty folder — <a href="?edit">[CREATE]</a></p>
+{{end}}
 {{end}}
 {{if or .Content .SpecialContent}}
-<script src="{{asset "page/content.js"}}"></script>
+<script src="/_/page/content.js"></script>
-{{if not .SuppressTOC}}<script src="{{asset "page/toc.js"}}"></script>{{end}}
+{{if not .SuppressTOC}}<script src="/_/page/toc.js"></script>{{end}}
-<script src="{{asset "page/tasks.js"}}"></script>
+<script src="/_/page/tasks.js"></script>
 {{end}}
 {{if .Content}}
-<script src="{{asset "page/sections.js"}}"></script>
+<script src="/_/page/sections.js"></script>
 {{end}}
-<script src="{{asset "page/contents.js"}}"></script>
+<script src="/_/page/contents.js"></script>
 {{end}}
 
 {{define "aside"}}{{if .SidebarWidget}}<aside class="sidebar">{{.SidebarWidget}}</aside>{{end}}{{end}}

assets/quickadd.html

@@ -4,8 +4,8 @@
         <meta charset="UTF-8" />
         <meta name="viewport" content="width=device-width, initial-scale=1" />
         <title>Save link</title>
-        <link rel="icon" href="{{asset "favicon.ico"}}" />
+        <link rel="icon" href="/_/favicon.ico" />
-        <link rel="stylesheet" href="{{asset "style.css"}}" />
+        <link rel="stylesheet" href="/_/style.css" />
         <style>
             body { padding: 0.8rem; }
             .qa-form { display: flex; flex-direction: column; gap: 0.5rem; }

assets/search/main.html

@@ -1,4 +1,4 @@
-{{define "headScripts"}}<script src="{{asset "search/actions.js"}}"></script>{{end}}
+{{define "headScripts"}}<script src="/_/search/actions.js"></script>{{end}}
 
 {{define "searchQuery"}}{{.Query}}{{end}}
 
@@ -43,7 +43,7 @@
 {{end}}
 
 {{define "headerActions"}}
-<button class="btn btn-block" onclick="rebuildIndex()" title="Rebuild search index"><span class="btn-icon">{{icon "rebuild"}}</span><span class="btn-label">REBUILD INDEX</span></button>
+<button class="btn btn-block" onclick="rebuildIndex()" title="Rebuild search index">REBUILD INDEX</button>
 {{end}}
 
 {{define "footerExtras"}}

assets/style.css

@@ -26,6 +26,17 @@
     --danger-hover: #d03467;
     --overlay: rgba(0, 0, 0, 0.55);
 
+    /* JSON Canvas preset colours "1".."6" (red, orange, yellow, green, cyan,
+       purple), pulled toward the app palette so a canvas does not look like a
+       different program. Hex colours in a .canvas file pass through untouched. */
+    --canvas-1: #e05555;
+    --canvas-2: #e08a3c;
+    --canvas-3: #d9b03c;
+    --canvas-4: #5aab64;
+    --canvas-5: #01b6c4;
+    --canvas-6: #a069c4;
+    --canvas-edge: #9a9a9a;
+
     --border: 1px solid var(--secondary);
     --border-dashed: 1px dashed var(--secondary);
     --border-guide: 1px solid var(--bg-panel-hover);
@@ -48,28 +59,6 @@
     --reading-width: 60rem;
 }
 
-/* Cross-document view transitions: page navigations stay full reloads, but the
-   browser holds the old frame until the new page is ready and swaps them
-   without a blank flash. The header and tree rail are named so they swap in
-   place (no crossfade) — only the rest of the page fades, and only briefly. */
-@view-transition { navigation: auto; }
-body > header { view-transition-name: app-header; }
-.tree-sidebar { view-transition-name: tree-sidebar; }
-::view-transition-group(*),
-::view-transition-old(*),
-::view-transition-new(*) { animation-duration: 0.12s; }
-::view-transition-group(app-header),
-::view-transition-group(tree-sidebar),
-::view-transition-old(app-header),
-::view-transition-new(app-header),
-::view-transition-old(tree-sidebar),
-::view-transition-new(tree-sidebar) { animation: none; }
-@media (prefers-reduced-motion: reduce) {
-    ::view-transition-group(*),
-    ::view-transition-old(*),
-    ::view-transition-new(*) { animation: none; }
-}
-
 /* Anchor / TOC jumps are handled by the .center scroll container's own
    scroll-padding-top (the header no longer overlaps content in the app-shell),
    so no html-level scroll padding is needed. */
@@ -411,10 +400,6 @@ main > h2 {
 .dropdown-menu.scrollable { max-height: 23rem; overflow-y: auto; }
 
 .actions-special > .btn {text-align: left;}
-/* Header actions carry an icon and a label: the mobile dropdown shows the
-   label, the inline desktop bar (see responsive block) the icon. */
-.btn-icon { display: none; }
-.btn-icon svg { display: block; }
 
 /* === Suggestion dropdown (header search + editor link picker) ===
    Anchored to a position:relative host. Mirrors .dropdown-menu visuals with
@@ -823,46 +808,13 @@ aside.sidebar:empty { display: none; }
 .diary-cal-grid td.cal-current,
 .diary-cal-grid td.cal-current a { color: var(--primary-hover); }
 .btn-block.cal-current { color: var(--primary-hover); }
-/* Calendar events and weight under a diary day heading. */
-.diary-day-cal { margin: var(--space-3) 0 0; }
-.diary-day-cal p { margin: 0; }
-
-/* === Calendars ===
-   Header maintenance chip + dropdown, and the calendars folder page. */
-.maint-toggle { display: inline-flex; align-items: center; }
-.maint-count { margin-left: 0.3rem; }
-.maint-toggle.is-idle { color: var(--text-muted); }
-.maint-menu {
-    min-width: 20rem;
-    max-width: calc(100vw - 2rem);
-    padding: var(--space-2) var(--space-3);
-    white-space: normal;
-}
-/* Two columns so dates line up; an empty when-cell keeps the grid intact. */
-.maint-list {
-    display: grid;
-    grid-template-columns: max-content 1fr;
-    column-gap: var(--space-2);
-    row-gap: 0.15rem;
-    font-size: var(--font-sm);
-}
-.maint-list > .muted { grid-column: 1 / -1; }
-.maint-list + .panel-header { margin-top: var(--space-3); }
-.maint-when { color: var(--text-muted); white-space: nowrap; }
-.maint-all { margin-top: var(--space-3); padding: 0.3rem 0 0; border-top: var(--border-dashed); }
-.cal-scroll { overflow-x: auto; }
-.cal-table .nowrap { white-space: nowrap; }
-.cal-error { color: var(--danger); font-size: var(--font-sm); }
-.cal-sync { margin-top: var(--space-3); }
 
 /* === Fitness dashboard ===
    Server-rendered inline SVG charts. Geometry comes precomputed from Go;
    colors and strokes are applied here via classes so the inline SVG follows
    the theme palette. */
-.fitness-chart { position: relative; padding: var(--space-3); }
+.fitness-chart { padding: var(--space-3); }
 .fitness-chart-header { margin-bottom: var(--space-2); }
-.fitness-controls { gap: var(--space-3); }
-.fitness-absolute { display: flex; align-items: center; gap: var(--space-1); font-size: var(--font-sm); color: var(--text-muted); }
 .fitness-range { width: auto; font-size: var(--font-sm); }
 .fitness-empty {
     border: var(--border-dashed);
@@ -876,24 +828,8 @@ aside.sidebar:empty { display: none; }
 .fitness-svg .chart-label { fill: var(--text-muted); font-size: var(--font-xs); }
 .fitness-svg .chart-line { fill: none; stroke: var(--link); stroke-width: 1.5; }
 .fitness-svg .chart-dot { fill: var(--link); }
-.fitness-svg.is-dense .chart-dot { display: none; }
+.fitness-svg .chart-goal { stroke: var(--primary-hover); stroke-dasharray: 4 3; }
-.fitness-svg:not(.is-hover) :is(.chart-cursor, .chart-focus) { display: none; }
+.fitness-svg .chart-goal-label { fill: var(--primary-hover); font-size: var(--font-xs); }
-.fitness-svg .chart-cursor { stroke: var(--text-muted); stroke-dasharray: 2 2; }
-.fitness-svg .chart-focus { fill: var(--link-hover); stroke: var(--bg); stroke-width: 1.5; }
-.fitness-svg .chart-goal { stroke: var(--danger); stroke-dasharray: 4 3; }
-.fitness-svg .chart-goal-label { fill: var(--danger-hover); font-size: var(--font-xs); }
-.fitness-tip {
-    position: absolute;
-    display: flex;
-    flex-direction: column;
-    padding: var(--space-1) var(--space-2);
-    background: var(--bg);
-    border: var(--border);
-    font-size: var(--font-sm);
-    white-space: nowrap;
-    pointer-events: none;
-}
-.fitness-tip[hidden] { display: none; }
 
 /* === Responsive === */
 @media (max-width: 1100px) {
@@ -915,9 +851,7 @@ aside.sidebar:empty { display: none; }
 @media (min-width: 1101px) {
     .actions-toggle, .actions-special {display: none;}
     .actions, .actions-menu, .actions.dropdown-menu.is-open {display: contents;}
-    .actions-menu .btn-block { width: auto; padding: 0; align-items: center; }
+    .actions-menu .btn-block { width: auto; padding: 0;}
-    .actions-menu .btn-icon { display: inline-block; }
-    .actions-menu .btn-label { display: none; }
 }
 
 @media (max-width: 600px) {
@@ -966,3 +900,319 @@ aside.sidebar:empty { display: none; }
     .list-item td.meta { grid-row: 2; grid-column: 2; text-align: left; }
     .toc {float: none; width: auto; max-width: none; margin: 0 0 var(--space-4);}
 }
+
+/* === Canvas ===
+   A canvas is an alternative view of a page (see canvas.go). The tab strip is
+   shared with the normal page template; everything below it only exists in
+   canvas mode. */
+
+/* --- view switcher (rendered on normal pages too) --- */
+.canvas-tabs {
+    gap: 0;
+    flex-wrap: wrap;
+    border-bottom: var(--border-dashed);
+    margin-bottom: var(--space-4);
+}
+.canvas-tab {
+    padding: var(--space-2) var(--space-3);
+    font-size: var(--font-sm);
+    color: var(--text-muted);
+    background: none;
+    border: 1px solid transparent;
+    border-bottom: none;
+    /* Overlap the strip's own border so the active tab joins it. */
+    margin-bottom: -1px;
+    font: inherit;
+    font-size: var(--font-sm);
+    cursor: pointer;
+}
+.canvas-tab:hover { color: var(--link-hover); }
+.canvas-tab.is-active {
+    color: var(--text);
+    border-color: var(--secondary);
+    background: var(--bg-panel);
+}
+.canvas-tab-add { color: var(--secondary); }
+
+/* --- full-bleed view mode ---
+   The canvas owns the viewport instead of the centred reading column: main
+   loses its max-width and padding, and the centre column stops scrolling so the
+   surface can handle pan itself. */
+body.canvas-mode .center { overflow: hidden; }
+body.canvas-mode main {
+    max-width: none;
+    padding: 0;
+    flex: 1 1 auto;
+    min-height: 0;
+    display: flex;
+    flex-direction: column;
+}
+body.canvas-mode footer { max-width: none; }
+body.canvas-mode .canvas-tabs { margin: 0; padding: var(--space-2) var(--space-4) 0; }
+
+.canvas-app {
+    display: flex;
+    flex-direction: column;
+    flex: 1 1 auto;
+    min-height: 0;
+}
+
+.canvas-toolbar {
+    display: flex;
+    flex-wrap: wrap;
+    gap: var(--space-1);
+    padding: 0.4rem 0.6rem;
+    background: var(--bg-panel-hover);
+    border-top: var(--border);
+    border-bottom: var(--border);
+    flex: 0 0 auto;
+}
+.canvas-status { margin-left: auto; padding-left: var(--space-3); }
+.canvas-swatch {
+    display: inline-block;
+    width: 0.7em;
+    height: 0.7em;
+    vertical-align: middle;
+    margin-right: 0.3em;
+    border: 1px solid var(--bg);
+}
+.canvas-swatch[data-swatch="1"] { background: var(--canvas-1); }
+.canvas-swatch[data-swatch="2"] { background: var(--canvas-2); }
+.canvas-swatch[data-swatch="3"] { background: var(--canvas-3); }
+.canvas-swatch[data-swatch="4"] { background: var(--canvas-4); }
+.canvas-swatch[data-swatch="5"] { background: var(--canvas-5); }
+.canvas-swatch[data-swatch="6"] { background: var(--canvas-6); }
+
+/* --- surface, world, layers ---
+   touch-action:none hands every touch gesture to the pointer handlers; without
+   it the browser claims one-finger drags for scrolling and two-finger for page
+   zoom, and neither reaches the canvas. */
+.canvas-surface {
+    position: relative;
+    flex: 1 1 auto;
+    min-height: 0;
+    overflow: hidden;
+    touch-action: none;
+    outline: none;
+    cursor: grab;
+    background-image: radial-gradient(circle, var(--bg-panel-hover) 1px, transparent 1px);
+    background-repeat: repeat;
+}
+.canvas-surface.is-grid-hidden { background-image: none; }
+
+/* The world is a zero-size anchor: all of its content is absolutely positioned
+   in world coordinates and the whole thing is moved by one transform, so pan
+   and zoom never touch a single node's layout. */
+.canvas-world {
+    position: absolute;
+    top: 0;
+    left: 0;
+    width: 0;
+    height: 0;
+    transform-origin: 0 0;
+    will-change: transform;
+}
+.canvas-layer { position: absolute; top: 0; left: 0; }
+/* Drawn in world coordinates with no viewport of its own; overflow:visible is
+   what lets it paint outside its 1x1 box, including at negative coordinates. */
+.canvas-edges {
+    position: absolute;
+    top: 0;
+    left: 0;
+    width: 1px;
+    height: 1px;
+    overflow: visible;
+}
+
+/* --- nodes --- */
+.canvas-node {
+    position: absolute;
+    display: flex;
+    flex-direction: column;
+    border: 1px solid var(--node-accent, var(--secondary));
+    background: var(--bg-panel);
+    /* Visible so the connection ports and resize handles, which sit on the
+       border, are not clipped; the body clips its own content instead. */
+    overflow: visible;
+    contain: layout paint;
+}
+.canvas-node[data-color="1"] { --node-accent: var(--canvas-1); }
+.canvas-node[data-color="2"] { --node-accent: var(--canvas-2); }
+.canvas-node[data-color="3"] { --node-accent: var(--canvas-3); }
+.canvas-node[data-color="4"] { --node-accent: var(--canvas-4); }
+.canvas-node[data-color="5"] { --node-accent: var(--canvas-5); }
+.canvas-node[data-color="6"] { --node-accent: var(--canvas-6); }
+.canvas-node.is-selected { outline: 2px solid var(--primary-hover); outline-offset: 1px; }
+.canvas-node.is-edge-target { outline: 2px dashed var(--link); outline-offset: 1px; }
+
+.canvas-node-body {
+    flex: 1 1 auto;
+    min-height: 0;
+    overflow: auto;
+    padding: var(--space-3);
+    font-size: var(--font-sm);
+}
+.canvas-node-body.content { margin-bottom: 0; }
+.canvas-node-body > :first-child { margin-top: 0; }
+.canvas-node-body > :last-child { margin-bottom: 0; }
+.canvas-node-body h1 { font-size: 1.1rem; }
+.canvas-node-body h2 { font-size: 1rem; }
+.canvas-node-body h3 { font-size: 0.95rem; }
+/* Task checkboxes are rendered enabled for pages, where page/tasks.js writes
+   the toggle back to index.md. Inside a canvas node there is no such wiring and
+   the markdown lives in the .canvas file, so a click would be a lie. */
+.canvas-node-body .task-checkbox { pointer-events: none; }
+
+.canvas-node-title {
+    flex: 0 0 auto;
+    padding: var(--space-1) var(--space-3);
+    font-size: var(--font-xs);
+    color: var(--text-muted);
+    border-bottom: var(--border-dashed);
+}
+
+/* A transcluded image or player fills its node edge to edge. */
+.canvas-node-body:has(> .canvas-media) { padding: 0; overflow: hidden; }
+.canvas-media { display: block; width: 100%; height: 100%; }
+.canvas-media img { display: block; width: 100%; height: 100%; object-fit: contain; }
+.canvas-broken { color: var(--danger-hover); }
+.canvas-file-fallback { padding: var(--space-2) 0; }
+
+.canvas-link-card {
+    display: flex;
+    flex-direction: column;
+    gap: var(--space-1);
+    align-items: flex-start;
+    max-width: 100%;
+}
+.canvas-link-host { color: var(--link); }
+.canvas-link-url { font-size: var(--font-xs); color: var(--text-muted); max-width: 100%; }
+.link-favicon { vertical-align: middle; margin-right: 3px; }
+
+.canvas-node-group {
+    background: rgba(255, 255, 255, 0.03);
+    border: 1px dashed var(--node-accent, var(--bg-panel-hover));
+    background-position: center;
+}
+.canvas-node-group[data-bg-style="cover"] { background-size: cover; }
+.canvas-node-group[data-bg-style="ratio"] { background-size: contain; background-repeat: no-repeat; }
+.canvas-node-group[data-bg-style="repeat"] { background-repeat: repeat; }
+.canvas-node-group .canvas-node-body { display: none; }
+.canvas-group-label {
+    padding: var(--space-2) var(--space-3);
+    font-size: var(--font-sm);
+    color: var(--text-muted);
+}
+
+/* --- ports and handles ---
+   Both are positioned on the node border (the negative margin centres them on
+   it) and stay invisible until the node is hovered or selected, so a dense
+   canvas is not covered in dots. */
+.canvas-port {
+    position: absolute;
+    width: 12px;
+    height: 12px;
+    margin: -6px;
+    border-radius: 50%;
+    background: var(--bg);
+    border: 1px solid var(--secondary);
+    opacity: 0;
+    cursor: crosshair;
+}
+.canvas-node:hover .canvas-port,
+.canvas-node.is-selected .canvas-port { opacity: 1; }
+.canvas-port:hover { background: var(--primary-hover); }
+.canvas-port-top { top: 0; left: 50%; }
+.canvas-port-bottom { top: 100%; left: 50%; }
+.canvas-port-left { top: 50%; left: 0; }
+.canvas-port-right { top: 50%; left: 100%; }
+
+.canvas-handle {
+    position: absolute;
+    width: 10px;
+    height: 10px;
+    margin: -5px;
+    background: var(--primary-hover);
+    opacity: 0;
+}
+.canvas-node.is-selected .canvas-handle { opacity: 1; }
+.canvas-handle-nw { top: 0; left: 0; cursor: nwse-resize; }
+.canvas-handle-ne { top: 0; left: 100%; cursor: nesw-resize; }
+.canvas-handle-se { top: 100%; left: 100%; cursor: nwse-resize; }
+.canvas-handle-sw { top: 100%; left: 0; cursor: nesw-resize; }
+
+/* --- edges ---
+   The hit path is a fat transparent stroke under the visible curve: a 2px
+   bezier is effectively unclickable without it. */
+.canvas-edge-hit {
+    stroke: transparent;
+    stroke-width: 16;
+    pointer-events: stroke;
+    cursor: pointer;
+}
+.canvas-edge-line { stroke-width: 2; pointer-events: none; }
+.canvas-edge-head { pointer-events: none; }
+.canvas-edge.is-selected .canvas-edge-line { stroke: var(--primary-hover); stroke-width: 3; }
+.canvas-edge.is-selected .canvas-edge-head { fill: var(--primary-hover); }
+.canvas-edge-label {
+    font-family: "Iosevka Etoile", monospace;
+    font-size: 12px;
+    fill: var(--text);
+    /* A stroke painted under the fill gives the label a halo against whatever
+       it overlaps, without measuring a background rect. */
+    stroke: var(--bg);
+    stroke-width: 4;
+    paint-order: stroke;
+    pointer-events: none;
+}
+.canvas-edge-temp {
+    stroke: var(--primary-hover);
+    stroke-width: 2;
+    stroke-dasharray: 6 4;
+    pointer-events: none;
+}
+
+/* --- overlays --- */
+.canvas-marquee {
+    position: absolute;
+    border: 1px dashed var(--primary-hover);
+    background: rgba(214, 77, 149, 0.12);
+    pointer-events: none;
+}
+.canvas-hint {
+    position: absolute;
+    top: 50%;
+    left: 50%;
+    transform: translate(-50%, -50%);
+    max-width: 30rem;
+    padding: var(--space-4);
+    text-align: center;
+    pointer-events: none;
+}
+
+/* The node editor is fixed to the viewport rather than mounted in the zoomed
+   world: CodeMirror measures itself in device pixels and a scaled ancestor
+   breaks its caret and selection maths. */
+.canvas-editor {
+    position: fixed;
+    z-index: 60;
+    display: flex;
+    flex-direction: column;
+}
+.canvas-editor .panel-header { padding: var(--space-2) var(--space-3); margin-bottom: 0; }
+.canvas-editor-mount { flex: 1 1 auto; min-height: 0; overflow: auto; }
+.canvas-editor-mount .cm-editor { height: 100%; }
+/* The shared editor theme sets a 60vh floor for the full-page editor; in a
+   node-sized panel that would force a scrollbar at every size. The theme is
+   injected at runtime and lands after this sheet, so it needs overriding. */
+.canvas-editor-mount .cm-scroller { min-height: 0 !important; }
+
+@media (max-width: 600px) {
+    .canvas-toolbar { gap: var(--space-2); padding: var(--space-2); }
+    .canvas-toolbar .btn-tool { padding: 0.2rem 0.4rem; }
+    body.canvas-mode .canvas-tabs { padding: var(--space-2) var(--space-2) 0; }
+    /* Touch has no hover, so ports would never appear; show them on selection
+       only and make both targets finger-sized. */
+    .canvas-port { width: 16px; height: 16px; margin: -8px; }
+    .canvas-handle { width: 14px; height: 14px; margin: -7px; }
+}

assets/tree-sidebar.js

@@ -40,7 +40,6 @@
     }
   })()
   var activeRow = null
-  var live = false // set once the fetched tree is on screen
 
   function disabledRow(text) {
     var row = document.createElement("div")
@@ -85,8 +84,7 @@
     var childrenEl = null
     var loaded = false
     var isOpen = false
-    var isLeaf = !entry.hasChildren
+    var isLeaf = false
-    if (isLeaf) chevron.classList.add("is-leaf")
 
     function ensureChildrenEl() {
       if (!childrenEl) {
@@ -170,26 +168,15 @@
   }
 
   function render() {
-    // If the layout pre-painted a snapshot of the previous page's tree, keep it
+    container.textContent = ""
-    // on screen and build the live tree off-DOM, swapping it in once ready —
-    // no "…" placeholder, no scroll jump.
     var listing = document.createElement("div")
-    var hasSnapshot = container.firstChild !== null
+    container.appendChild(listing)
-    if (!hasSnapshot) {
+    listing.appendChild(disabledRow("…"))
-      container.appendChild(listing)
-      listing.appendChild(disabledRow("…"))
-    }
 
     fetchFolder("/", activePath === "/" ? "" : activePath)
       .then(function (resp) {
         listing.textContent = ""
         renderInto(listing, "/", resp.entries)
-        if (hasSnapshot) {
-          var top = container.scrollTop
-          container.replaceChildren(listing)
-          container.scrollTop = top
-        }
-        live = true
         if (activeRow) {
           try {
             activeRow.scrollIntoView({ block: "nearest" })
@@ -197,34 +184,17 @@
         }
       })
       .catch(function () {
-        live = false
-        container.replaceChildren(listing)
         listing.textContent = ""
         var err = document.createElement("div")
         err.className = "tree-row"
         err.textContent = "(failed — tap to retry)"
         err.addEventListener("click", function () {
-          container.textContent = ""
           render()
         })
         listing.appendChild(err)
       })
   }
 
-  // Snapshot the tree (markup + scroll) on the way out so the next page's
-  // layout can paint it immediately. Skipped until the live tree has rendered,
-  // so a placeholder or error row never becomes the snapshot. The active
-  // highlight is left out; the next page marks its own row.
-  window.addEventListener("pagehide", function () {
-    if (!live) return
-    if (activeRow) activeRow.classList.remove("is-active")
-    var html = container.innerHTML
-    if (activeRow) activeRow.classList.add("is-active") // bfcache may restore this page
-    try {
-      sessionStorage.setItem("tree-snapshot", JSON.stringify({ html: html, top: container.scrollTop }))
-    } catch (e) {}
-  })
-
   function setupMenuItem() {
     var specials = document.querySelector(".actions-special")
     if (!specials) return

calendar.go

@@ -1,677 +0,0 @@
-package main
-
-import (
-	"bytes"
-	"errors"
-	"fmt"
-	"log"
-	"math"
-	"os"
-	"path/filepath"
-	"regexp"
-	"sort"
-	"strconv"
-	"strings"
-	"sync"
-	"time"
-
-	"github.com/emersion/go-ical"
-	"github.com/teambition/rrule-go"
-)
-
-// calendarsDir is the absolute path of the calendars folder (-calendars).
-// Empty disables the diary lines, the maintenance widget and the sync. Every
-// calendar is one <Name>.ics file in this folder; the folder's .page-settings
-// assigns calendars to roles and holds the CalDAV sync credentials.
-var calendarsDir string
-
-// === Settings ===
-
-type calendarSettings struct {
-	// Roles: calendar names (file basenames without .ics).
-	Diary       []string
-	Weight      []string
-	Maintenance []string
-
-	CaldavURL    string
-	CaldavUser   string
-	CaldavPass   string
-	SyncInterval time.Duration // 0 = startup and manual only
-}
-
-// readCalendarSettings reads the calendar keys from dir's .page-settings.
-// Read on every use, so edits apply without a restart.
-func readCalendarSettings(dir string) calendarSettings {
-	kv := readSettingsFile(dir)
-	s := calendarSettings{
-		Diary:        splitCalendarList(kv["diary"]),
-		Weight:       splitCalendarList(kv["weight"]),
-		Maintenance:  splitCalendarList(kv["maintenance"]),
-		CaldavURL:    kv["caldav-url"],
-		CaldavUser:   kv["caldav-user"],
-		CaldavPass:   kv["caldav-pass"],
-		SyncInterval: 15 * time.Minute,
-	}
-	if v, ok := kv["sync-interval"]; ok {
-		if d, err := time.ParseDuration(v); err == nil && d >= 0 {
-			s.SyncInterval = d
-		}
-	}
-	return s
-}
-
-func splitCalendarList(v string) []string {
-	var out []string
-	for _, name := range strings.Split(v, ",") {
-		if name = strings.TrimSpace(name); name != "" {
-			out = append(out, name)
-		}
-	}
-	return out
-}
-
-// calendarPath returns the file of calendar name in dir, or "" when the name
-// would escape the folder.
-func calendarPath(dir, name string) string {
-	if name == "" || strings.ContainsAny(name, `/\`) || strings.HasPrefix(name, ".") {
-		return ""
-	}
-	return filepath.Join(dir, name+".ics")
-}
-
-// === Model ===
-
-// calEvent is one expanded occurrence.
-type calEvent struct {
-	Calendar string
-	UID      string
-	Summary  string
-	Start    time.Time // local time; all-day events start at local midnight
-	End      time.Time // exclusive
-	AllDay   bool
-	Stamp    time.Time  // LAST-MODIFIED, else DTSTAMP
-	Series   *calSeries // nil for single events
-}
-
-// calSeries describes a recurring event as a whole.
-type calSeries struct {
-	Calendar string
-	UID      string
-	Summary  string
-	Rule     string // human-readable, e.g. "every 2 weeks (Sa)"
-}
-
-// calItem is a parsed VEVENT: a single event, a recurring master, or a
-// RECURRENCE-ID override attached to its master.
-type calItem struct {
-	uid       string
-	summary   string
-	start     time.Time
-	end       time.Time
-	allDay    bool
-	days      int // all-day length in days; keeps occurrences DST-safe
-	stamp     time.Time
-	cancelled bool
-
-	set       *rrule.Set         // nil = single event
-	series    *calSeries         // set together with set
-	overrides map[int64]*calItem // RECURRENCE-ID (unix) → replacement
-}
-
-// calFile is one parsed calendar file.
-type calFile struct {
-	modTime time.Time
-	size    int64
-	items   []*calItem
-	events  int // VEVENT components in the file
-}
-
-// === Store ===
-
-// calStore caches parsed calendar files by path. An entry is reused while the
-// file's modtime and size are unchanged, so a request costs one stat per
-// calendar. Parsed files are never mutated, so callers may keep using a
-// snapshot after the lock is released.
-var calStore = struct {
-	sync.Mutex
-	files map[string]*calFile
-}{files: map[string]*calFile{}}
-
-// loadCalendar returns the parsed calendar at path; nil when it does not exist
-// or cannot be parsed (logged).
-func loadCalendar(path string) *calFile {
-	info, err := os.Stat(path)
-	if err != nil {
-		return nil
-	}
-	calStore.Lock()
-	defer calStore.Unlock()
-	if f := calStore.files[path]; f != nil && f.modTime.Equal(info.ModTime()) && f.size == info.Size() {
-		return f
-	}
-	data, err := os.ReadFile(path)
-	if err != nil {
-		return nil
-	}
-	f, err := parseCalendar(filepath.Base(path), data)
-	if err != nil {
-		log.Printf("calendar %s: %v", path, err)
-		delete(calStore.files, path)
-		return nil
-	}
-	f.modTime = info.ModTime()
-	f.size = info.Size()
-	calStore.files[path] = f
-	return f
-}
-
-// calendarOccurrences expands every event of the named calendars in dir that
-// overlaps [from, to). The result is sorted by start, then summary.
-func calendarOccurrences(dir string, names []string, from, to time.Time) []calEvent {
-	var out []calEvent
-	for _, name := range names {
-		p := calendarPath(dir, name)
-		if p == "" {
-			continue
-		}
-		f := loadCalendar(p)
-		if f == nil {
-			continue
-		}
-		for _, it := range f.items {
-			out = it.expand(name, from, to, out)
-		}
-	}
-	sort.SliceStable(out, func(i, j int) bool {
-		if !out[i].Start.Equal(out[j].Start) {
-			return out[i].Start.Before(out[j].Start)
-		}
-		return out[i].Summary < out[j].Summary
-	})
-	return out
-}
-
-func (it *calItem) occurrence(calendar string, start, end time.Time) calEvent {
-	return calEvent{
-		Calendar: calendar,
-		UID:      it.uid,
-		Summary:  it.summary,
-		Start:    start.In(time.Local),
-		End:      end.In(time.Local),
-		AllDay:   it.allDay,
-		Stamp:    it.stamp,
-	}
-}
-
-// overlaps reports whether [start, end) intersects [from, to). Zero-length
-// events count when they start inside the window.
-func overlaps(start, end, from, to time.Time) bool {
-	if !start.Before(to) {
-		return false
-	}
-	return end.After(from) || !start.Before(from)
-}
-
-// expand appends the item's occurrences in [from, to) to out.
-func (it *calItem) expand(calendar string, from, to time.Time, out []calEvent) []calEvent {
-	if it.cancelled {
-		return out
-	}
-	if it.set == nil {
-		if overlaps(it.start, it.end, from, to) {
-			out = append(out, it.occurrence(calendar, it.start, it.end))
-		}
-		return out
-	}
-	// Start the search early enough to catch occurrences that began before
-	// the window but still run into it.
-	after := from.Add(-it.end.Sub(it.start)).Add(-48 * time.Hour)
-	for _, s := range it.set.Between(after, to, true) {
-		if _, overridden := it.overrides[s.Unix()]; overridden {
-			continue
-		}
-		e := it.occurrenceEnd(s)
-		if overlaps(s, e, from, to) {
-			ev := it.occurrence(calendar, s, e)
-			ev.Series = it.series
-			out = append(out, ev)
-		}
-	}
-	// Overrides are placed on their own dates: a moved occurrence can enter
-	// or leave the window independently of its original slot.
-	for _, o := range it.overrides {
-		if o.cancelled || !overlaps(o.start, o.end, from, to) {
-			continue
-		}
-		ev := o.occurrence(calendar, o.start, o.end)
-		ev.Series = it.series
-		out = append(out, ev)
-	}
-	return out
-}
-
-// occurrenceEnd returns the end of the occurrence starting at s.
-func (it *calItem) occurrenceEnd(s time.Time) time.Time {
-	if it.allDay {
-		return s.AddDate(0, 0, it.days)
-	}
-	return s.Add(it.end.Sub(it.start))
-}
-
-// === Parsing ===
-
-// calParser holds per-file parse state: the file name for log messages, the
-// TZIDs already warned about, and resolved locations.
-type calParser struct {
-	file   string
-	zones  map[string]*time.Location
-	warned map[string]bool
-}
-
-func parseCalendar(file string, data []byte) (*calFile, error) {
-	data = bytes.TrimPrefix(data, []byte{0xEF, 0xBB, 0xBF}) // UTF-8 BOM
-	cal, err := ical.NewDecoder(bytes.NewReader(data)).Decode()
-	if err != nil {
-		return nil, err
-	}
-	p := &calParser{file: file, zones: map[string]*time.Location{}, warned: map[string]bool{}}
-	f := &calFile{}
-	masters := map[string]*calItem{}
-	type override struct {
-		item    *calItem
-		recurID time.Time
-	}
-	var overrides []override
-	for _, comp := range cal.Children {
-		if comp.Name != ical.CompEvent {
-			continue
-		}
-		f.events++
-		it, recurID, err := p.item(comp)
-		if err != nil {
-			continue
-		}
-		if !recurID.IsZero() {
-			overrides = append(overrides, override{it, recurID})
-			continue
-		}
-		f.items = append(f.items, it)
-		if it.uid != "" {
-			masters[it.uid] = it
-		}
-	}
-	// Overrides can come before their master in the file, so attach them in
-	// a second pass. One without a recurring master is shown as a single event.
-	for _, o := range overrides {
-		m := masters[o.item.uid]
-		if m == nil || m.set == nil {
-			f.items = append(f.items, o.item)
-			continue
-		}
-		if o.item.summary == "" {
-			o.item.summary = m.summary
-		}
-		m.overrides[o.recurID.Unix()] = o.item
-	}
-	return f, nil
-}
-
-// item parses one VEVENT. recurID is non-zero for RECURRENCE-ID overrides.
-func (p *calParser) item(comp *ical.Component) (it *calItem, recurID time.Time, err error) {
-	startProp := comp.Props.Get(ical.PropDateTimeStart)
-	if startProp == nil {
-		return nil, time.Time{}, errors.New("no DTSTART")
-	}
-	starts, allDay, err := p.times(startProp)
-	if err != nil || len(starts) == 0 {
-		return nil, time.Time{}, fmt.Errorf("DTSTART: %v", err)
-	}
-	it = &calItem{start: starts[0], allDay: allDay}
-	it.uid = calText(comp.Props.Get(ical.PropUID))
-	it.summary = strings.TrimSpace(calText(comp.Props.Get(ical.PropSummary)))
-
-	it.end = it.start
-	if prop := comp.Props.Get(ical.PropDateTimeEnd); prop != nil {
-		if ends, _, err := p.times(prop); err == nil && len(ends) > 0 {
-			it.end = ends[0]
-		}
-	} else if prop := comp.Props.Get(ical.PropDuration); prop != nil {
-		if d, err := prop.Duration(); err == nil {
-			if allDay {
-				it.end = it.start.AddDate(0, 0, int(math.Round(d.Hours()/24)))
-			} else {
-				it.end = it.start.Add(d)
-			}
-		}
-	} else if allDay {
-		it.end = it.start.AddDate(0, 0, 1)
-	}
-	if it.end.Before(it.start) {
-		it.end = it.start
-	}
-	if allDay {
-		it.days = calendarDaysBetween(it.start, it.end)
-		if it.days < 1 {
-			it.days = 1
-		}
-		it.end = it.start.AddDate(0, 0, it.days)
-	}
-
-	if strings.EqualFold(calText(comp.Props.Get(ical.PropStatus)), "CANCELLED") {
-		it.cancelled = true
-	}
-	for _, name := range []string{ical.PropLastModified, ical.PropDateTimeStamp} {
-		if prop := comp.Props.Get(name); prop != nil {
-			if ts, _, err := p.times(prop); err == nil && len(ts) > 0 {
-				it.stamp = ts[0]
-				break
-			}
-		}
-	}
-
-	if prop := comp.Props.Get(ical.PropRecurrenceID); prop != nil {
-		ids, _, err := p.times(prop)
-		if err != nil || len(ids) == 0 {
-			return nil, time.Time{}, fmt.Errorf("RECURRENCE-ID: %v", err)
-		}
-		return it, ids[0], nil
-	}
-
-	rule := comp.Props.Get(ical.PropRecurrenceRule)
-	rdates := comp.Props.Values(ical.PropRecurrenceDates)
-	if rule == nil && len(rdates) == 0 {
-		return it, time.Time{}, nil
-	}
-	set := &rrule.Set{}
-	ruleText := ""
-	if rule != nil {
-		opt, err := rrule.StrToROptionInLocation(rule.Value, it.start.Location())
-		if err != nil {
-			p.warn("rrule:"+rule.Value, "cannot parse RRULE %q of %q: %v", rule.Value, it.summary, err)
-			return it, time.Time{}, nil
-		}
-		opt.Dtstart = it.start
-		r, err := rrule.NewRRule(*opt)
-		if err != nil {
-			p.warn("rrule:"+rule.Value, "cannot build RRULE %q of %q: %v", rule.Value, it.summary, err)
-			return it, time.Time{}, nil
-		}
-		set.RRule(r)
-		ruleText = describeRRule(opt)
-	} else {
-		// Without an RRULE the set only holds RDATEs; DTSTART is always the
-		// first occurrence.
-		set.RDate(it.start)
-		ruleText = "on selected dates"
-	}
-	for i := range rdates {
-		if ts, _, err := p.times(&rdates[i]); err == nil {
-			for _, t := range ts {
-				set.RDate(t)
-			}
-		}
-	}
-	for _, prop := range comp.Props.Values(ical.PropExceptionDates) {
-		if ts, _, err := p.times(&prop); err == nil {
-			for _, t := range ts {
-				set.ExDate(t)
-			}
-		}
-	}
-	it.set = set
-	it.overrides = map[int64]*calItem{}
-	it.series = &calSeries{
-		Calendar: strings.TrimSuffix(p.file, ".ics"),
-		UID:      it.uid,
-		Summary:  it.summary,
-		Rule:     ruleText,
-	}
-	return it, time.Time{}, nil
-}
-
-// calText unescapes a TEXT value. Unlike go-ical's Text it keeps unescaped
-// commas: clients write titles like "95,6kg" without the required backslash,
-// and go-ical would cut them at the comma. Unknown escapes are kept as is.
-func calText(prop *ical.Prop) string {
-	if prop == nil {
-		return ""
-	}
-	v := prop.Value
-	if !strings.Contains(v, `\`) {
-		return v
-	}
-	var sb strings.Builder
-	for i := 0; i < len(v); i++ {
-		c := v[i]
-		if c != '\\' || i+1 == len(v) {
-			sb.WriteByte(c)
-			continue
-		}
-		i++
-		switch n := v[i]; n {
-		case 'n', 'N':
-			sb.WriteByte('\n')
-		case '\\', ';', ',':
-			sb.WriteByte(n)
-		default:
-			sb.WriteByte('\\')
-			sb.WriteByte(n)
-		}
-	}
-	return sb.String()
-}
-
-// times parses a DATE or DATE-TIME property. Comma-separated lists (EXDATE,
-// RDATE) yield several values. Dates and floating times use the local zone; an
-// unknown TZID falls back to it with a warning.
-func (p *calParser) times(prop *ical.Prop) ([]time.Time, bool, error) {
-	loc := time.Local
-	if tzid := prop.Params.Get(ical.PropTimezoneID); tzid != "" {
-		loc = p.zone(tzid)
-	}
-	var out []time.Time
-	allDay := false
-	for _, v := range strings.Split(prop.Value, ",") {
-		v = strings.TrimSpace(v)
-		var t time.Time
-		var err error
-		switch {
-		case len(v) == 8:
-			t, err = time.ParseInLocation("20060102", v, time.Local)
-			allDay = true
-		case len(v) == 16 && strings.HasSuffix(v, "Z"):
-			t, err = time.Parse("20060102T150405Z", v)
-		case len(v) == 15:
-			t, err = time.ParseInLocation("20060102T150405", v, loc)
-		default:
-			err = fmt.Errorf("unsupported value %q", v)
-		}
-		if err != nil {
-			return nil, false, err
-		}
-		out = append(out, t)
-	}
-	return out, allDay, nil
-}
-
-func (p *calParser) zone(tzid string) *time.Location {
-	if loc, ok := p.zones[tzid]; ok {
-		return loc
-	}
-	loc, err := time.LoadLocation(tzid)
-	if err != nil {
-		// Some clients prefix the IANA name, e.g.
-		// "/freeassociation.sourceforge.net/Tzfile/Europe/Berlin".
-		parts := strings.Split(strings.Trim(tzid, "/"), "/")
-		if len(parts) >= 2 {
-			loc, err = time.LoadLocation(strings.Join(parts[len(parts)-2:], "/"))
-		}
-	}
-	if err != nil {
-		p.warn("tz:"+tzid, "unknown TZID %q, using local time", tzid)
-		loc = time.Local
-	}
-	p.zones[tzid] = loc
-	return loc
-}
-
-func (p *calParser) warn(key, format string, args ...any) {
-	if p.warned[key] {
-		return
-	}
-	p.warned[key] = true
-	log.Printf("calendar %s: "+format, append([]any{p.file}, args...)...)
-}
-
-// calendarDaysBetween counts calendar days from a to b (both local midnights),
-// independent of DST shifts.
-func calendarDaysBetween(a, b time.Time) int {
-	ay, am, ad := a.Date()
-	by, bm, bd := b.Date()
-	ua := time.Date(ay, am, ad, 0, 0, 0, 0, time.UTC)
-	ub := time.Date(by, bm, bd, 0, 0, 0, 0, time.UTC)
-	return int(ub.Sub(ua).Hours() / 24)
-}
-
-// === Formatting ===
-
-var germanWeekdays = [...]string{"So", "Mo", "Di", "Mi", "Do", "Fr", "Sa"}
-
-// calDayLabel formats a date as "Sa 27.09.".
-func calDayLabel(t time.Time) string {
-	return fmt.Sprintf("%s %02d.%02d.", germanWeekdays[t.Weekday()], t.Day(), int(t.Month()))
-}
-
-// describeRRule turns common rules into short text ("weekly (Mo)",
-// "every 2 weeks (Sa)", "monthly (day 1)"). Anything with parts it does not
-// know falls back to the raw rule.
-func describeRRule(opt *rrule.ROption) string {
-	if len(opt.Bysetpos) > 0 || len(opt.Byyearday) > 0 || len(opt.Byweekno) > 0 ||
-		len(opt.Byhour) > 0 || len(opt.Byminute) > 0 || len(opt.Bysecond) > 0 {
-		return opt.RRuleString()
-	}
-	units := map[rrule.Frequency][2]string{
-		rrule.DAILY:   {"daily", "days"},
-		rrule.WEEKLY:  {"weekly", "weeks"},
-		rrule.MONTHLY: {"monthly", "months"},
-		rrule.YEARLY:  {"yearly", "years"},
-	}
-	u, ok := units[opt.Freq]
-	if !ok {
-		return opt.RRuleString()
-	}
-	text := u[0]
-	if opt.Interval > 1 {
-		text = fmt.Sprintf("every %d %s", opt.Interval, u[1])
-	}
-	var details []string
-	for _, wd := range opt.Byweekday {
-		name := germanWeekdays[(wd.Day()+1)%7]
-		if n := wd.N(); n != 0 {
-			name = strconv.Itoa(n) + ". " + name
-			if n == -1 {
-				name = "last " + germanWeekdays[(wd.Day()+1)%7]
-			}
-		}
-		details = append(details, name)
-	}
-	for _, d := range opt.Bymonthday {
-		details = append(details, fmt.Sprintf("day %d", d))
-	}
-	for _, m := range opt.Bymonth {
-		if m >= 1 && m <= 12 {
-			details = append(details, germanMonths[time.Month(m)])
-		}
-	}
-	if len(details) > 0 {
-		text += " (" + strings.Join(details, ", ") + ")"
-	}
-	return text
-}
-
-// === Diary lines ===
-
-// calDayLines is the calendar content shown under a diary day.
-type calDayLines struct {
-	Events string // "Feiertag, 10:00 Brunch, 19:30 Kino"
-	Weight string // "95,6 kg"
-}
-
-var weightTitle = regexp.MustCompile(`(?i)^\s*(\d+(?:[.,]\d+)?)\s*kg\s*$`)
-
-// calendarDayLines builds the diary lines for every day in [from, to), keyed
-// by "YYYY-MM-DD". Events come from the diary role, weights from the weight
-// role. Days without either are absent.
-func calendarDayLines(from, to time.Time) map[string]calDayLines {
-	out := map[string]calDayLines{}
-	if calendarsDir == "" {
-		return out
-	}
-	s := readCalendarSettings(calendarsDir)
-
-	type dayEvents struct{ allDay, timed []calEvent }
-	byDay := map[string]*dayEvents{}
-	for _, ev := range calendarOccurrences(calendarsDir, s.Diary, from, to) {
-		if ev.AllDay {
-			// Multi-day all-day events show on every day they cover.
-			for d := ev.Start; d.Before(ev.End); d = d.AddDate(0, 0, 1) {
-				key := d.Format("2006-01-02")
-				if byDay[key] == nil {
-					byDay[key] = &dayEvents{}
-				}
-				byDay[key].allDay = append(byDay[key].allDay, ev)
-			}
-			continue
-		}
-		key := ev.Start.Format("2006-01-02")
-		if byDay[key] == nil {
-			byDay[key] = &dayEvents{}
-		}
-		byDay[key].timed = append(byDay[key].timed, ev)
-	}
-	for key, d := range byDay {
-		sort.SliceStable(d.allDay, func(i, j int) bool { return d.allDay[i].Summary < d.allDay[j].Summary })
-		var parts []string
-		for _, ev := range d.allDay {
-			if ev.Summary != "" {
-				parts = append(parts, ev.Summary)
-			}
-		}
-		// Timed events are already sorted by start, then summary.
-		for _, ev := range d.timed {
-			parts = append(parts, strings.TrimSpace(ev.Start.Format("15:04")+" "+ev.Summary))
-		}
-		if len(parts) > 0 {
-			out[key] = calDayLines{Events: strings.Join(parts, ", ")}
-		}
-	}
-
-	for key, w := range calendarWeights(s, from, to) {
-		lines := out[key]
-		lines.Weight = strings.ReplaceAll(w, ".", ",") + " kg"
-		out[key] = lines
-	}
-	return out
-}
-
-// calendarWeights reads the weight role for [from, to): one entry per day,
-// keyed by "YYYY-MM-DD", holding the kg value with a '.' decimal separator.
-// Events whose title is not a weight are skipped; several entries on one day:
-// the last edited one wins.
-func calendarWeights(s calendarSettings, from, to time.Time) map[string]string {
-	out := map[string]string{}
-	stamps := map[string]time.Time{}
-	for _, ev := range calendarOccurrences(calendarsDir, s.Weight, from, to) {
-		m := weightTitle.FindStringSubmatch(ev.Summary)
-		if m == nil {
-			continue
-		}
-		key := ev.Start.Format("2006-01-02")
-		if prev, ok := stamps[key]; ok && ev.Stamp.Before(prev) {
-			continue
-		}
-		stamps[key] = ev.Stamp
-		out[key] = strings.ReplaceAll(m[1], ",", ".")
-	}
-	return out
-}

calendar_test.go

@@ -1,283 +0,0 @@
-package main
-
-import (
-	"io"
-	"net/http"
-	"net/http/httptest"
-	"os"
-	"path/filepath"
-	"strings"
-	"testing"
-	"time"
-)
-
-// writeCal writes a VCALENDAR with the given VEVENT bodies to dir/name.ics.
-func writeCal(t *testing.T, dir, name string, events ...string) {
-	t.Helper()
-	var b strings.Builder
-	b.WriteString("BEGIN:VCALENDAR\r\nVERSION:2.0\r\nPRODID:test\r\n")
-	for _, ev := range events {
-		b.WriteString("BEGIN:VEVENT\r\n")
-		for _, line := range strings.Split(strings.TrimSpace(ev), "\n") {
-			b.WriteString(strings.TrimSpace(line) + "\r\n")
-		}
-		b.WriteString("END:VEVENT\r\n")
-	}
-	b.WriteString("END:VCALENDAR\r\n")
-	if err := os.WriteFile(filepath.Join(dir, name+".ics"), []byte(b.String()), 0644); err != nil {
-		t.Fatal(err)
-	}
-}
-
-func withBerlin(t *testing.T) {
-	t.Helper()
-	loc, err := time.LoadLocation("Europe/Berlin")
-	if err != nil {
-		t.Fatal(err)
-	}
-	prev := time.Local
-	time.Local = loc
-	t.Cleanup(func() { time.Local = prev })
-}
-
-func day(y int, m time.Month, d int) time.Time {
-	return time.Date(y, m, d, 0, 0, 0, 0, time.Local)
-}
-
-func summaries(evs []calEvent) []string {
-	var out []string
-	for _, ev := range evs {
-		out = append(out, ev.Start.Format("2006-01-02 15:04")+" "+ev.Summary)
-	}
-	return out
-}
-
-func assertStrings(t *testing.T, got, want []string) {
-	t.Helper()
-	if strings.Join(got, "\n") != strings.Join(want, "\n") {
-		t.Fatalf("got:\n  %s\nwant:\n  %s", strings.Join(got, "\n  "), strings.Join(want, "\n  "))
-	}
-}
-
-func TestCalendarSingleAndAllDay(t *testing.T) {
-	withBerlin(t)
-	dir := t.TempDir()
-	writeCal(t, dir, "P",
-		`UID:a
-		SUMMARY:Zahnarzt
-		DTSTART;TZID=Europe/Berlin:20261002T090000
-		DTEND;TZID=Europe/Berlin:20261002T100000`,
-		`UID:b
-		SUMMARY:Urlaub
-		DTSTART;VALUE=DATE:20261001
-		DTEND;VALUE=DATE:20261004`,
-		`UID:c
-		SUMMARY:UTC call
-		DTSTART:20261002T160000Z
-		DURATION:PT1H`,
-	)
-	got := summaries(calendarOccurrences(dir, []string{"P"}, day(2026, 10, 2), day(2026, 10, 3)))
-	assertStrings(t, got, []string{
-		"2026-10-01 00:00 Urlaub",
-		"2026-10-02 09:00 Zahnarzt",
-		"2026-10-02 18:00 UTC call",
-	})
-	// DTEND of all-day events is exclusive.
-	if got := calendarOccurrences(dir, []string{"P"}, day(2026, 10, 4), day(2026, 10, 5)); len(got) != 0 {
-		t.Fatalf("all-day event leaked past DTEND: %v", summaries(got))
-	}
-}
-
-func TestCalendarRecurrence(t *testing.T) {
-	withBerlin(t)
-	dir := t.TempDir()
-	writeCal(t, dir, "M",
-		`UID:backup
-		SUMMARY:Backup
-		DTSTART;TZID=Europe/Berlin:20260907T030000
-		DTEND;TZID=Europe/Berlin:20260907T040000
-		RRULE:FREQ=WEEKLY;BYDAY=MO
-		EXDATE;TZID=Europe/Berlin:20260914T030000,20260921T030000`,
-		`UID:backup
-		RECURRENCE-ID;TZID=Europe/Berlin:20260928T030000
-		SUMMARY:Backup (moved)
-		DTSTART;TZID=Europe/Berlin:20260929T050000
-		DTEND;TZID=Europe/Berlin:20260929T060000`,
-		`UID:backup
-		RECURRENCE-ID;TZID=Europe/Berlin:20261005T030000
-		DTSTART;TZID=Europe/Berlin:20261005T030000
-		STATUS:CANCELLED`,
-		`UID:sheets
-		SUMMARY:Bettwäsche
-		DTSTART;VALUE=DATE:20260905
-		RRULE:FREQ=WEEKLY;INTERVAL=2`,
-	)
-	got := summaries(calendarOccurrences(dir, []string{"M"}, day(2026, 9, 1), day(2026, 10, 20)))
-	assertStrings(t, got, []string{
-		"2026-09-05 00:00 Bettwäsche",
-		"2026-09-07 03:00 Backup",
-		"2026-09-19 00:00 Bettwäsche",
-		"2026-09-29 05:00 Backup (moved)",
-		"2026-10-03 00:00 Bettwäsche",
-		"2026-10-12 03:00 Backup",
-		"2026-10-17 00:00 Bettwäsche",
-		"2026-10-19 03:00 Backup",
-	})
-	// Wall-clock time survives the DST change on 2026-10-25.
-	got = summaries(calendarOccurrences(dir, []string{"M"}, day(2026, 10, 26), day(2026, 10, 27)))
-	assertStrings(t, got, []string{"2026-10-26 03:00 Backup"})
-
-	evs := calendarOccurrences(dir, []string{"M"}, day(2026, 9, 5), day(2026, 9, 8))
-	if evs[0].Series == nil || evs[0].Series.Rule != "every 2 weeks" {
-		t.Fatalf("sheets rule = %+v", evs[0].Series)
-	}
-	if evs[1].Series == nil || evs[1].Series.Rule != "weekly (Mo)" {
-		t.Fatalf("backup rule = %+v", evs[1].Series)
-	}
-}
-
-func TestCalendarUnknownTZIDFallsBack(t *testing.T) {
-	withBerlin(t)
-	dir := t.TempDir()
-	writeCal(t, dir, "P",
-		`UID:x
-		SUMMARY:Windows zone
-		DTSTART;TZID=W. Europe Standard Time:20261002T090000
-		DTEND;TZID=W. Europe Standard Time:20261002T100000`,
-		`UID:y
-		SUMMARY:Prefixed zone
-		DTSTART;TZID=/freeassociation.sourceforge.net/Tzfile/Europe/Berlin:20261002T110000`,
-	)
-	got := summaries(calendarOccurrences(dir, []string{"P"}, day(2026, 10, 2), day(2026, 10, 3)))
-	assertStrings(t, got, []string{
-		"2026-10-02 09:00 Windows zone",
-		"2026-10-02 11:00 Prefixed zone",
-	})
-}
-
-func TestCalendarDayLines(t *testing.T) {
-	withBerlin(t)
-	dir := t.TempDir()
-	prev := calendarsDir
-	calendarsDir = dir
-	t.Cleanup(func() { calendarsDir = prev })
-
-	if err := os.WriteFile(filepath.Join(dir, ".page-settings"),
-		[]byte("type = calendars\ndiary = Personal, Feiertage\nweight = Gewicht\nmaintenance = Maintainance\n"), 0644); err != nil {
-		t.Fatal(err)
-	}
-	writeCal(t, dir, "Personal",
-		`UID:1
-		SUMMARY:Kino
-		DTSTART;TZID=Europe/Berlin:20261003T193000`,
-		`UID:2
-		SUMMARY:Brunch\, Anna
-		DTSTART;TZID=Europe/Berlin:20261003T100000`,
-	)
-	writeCal(t, dir, "Feiertage",
-		`UID:3
-		SUMMARY:Tag der Deutschen Einheit
-		DTSTART;VALUE=DATE:20261003`,
-	)
-	writeCal(t, dir, "Gewicht",
-		`UID:4
-		SUMMARY:95.9 KG
-		DTSTART;VALUE=DATE:20261003
-		DTSTAMP:20261003T060000Z`,
-		`UID:5
-		SUMMARY:95,6kg
-		DTSTART;VALUE=DATE:20261003
-		DTSTAMP:20261003T070000Z`,
-		`UID:6
-		SUMMARY:not a weight
-		DTSTART;VALUE=DATE:20261004`,
-	)
-	writeCal(t, dir, "Maintainance",
-		`UID:7
-		SUMMARY:Backup
-		DTSTART;VALUE=DATE:20261003`,
-	)
-
-	lines := calendarDayLines(day(2026, 10, 1), day(2026, 10, 10))
-	want := calDayLines{
-		Events: "Tag der Deutschen Einheit, 10:00 Brunch, Anna, 19:30 Kino",
-		Weight: "95,6 kg",
-	}
-	if lines["2026-10-03"] != want {
-		t.Fatalf("got %+v, want %+v", lines["2026-10-03"], want)
-	}
-	if _, ok := lines["2026-10-04"]; ok {
-		t.Fatalf("unparsable weight produced a line: %+v", lines["2026-10-04"])
-	}
-}
-
-func TestCalendarSync(t *testing.T) {
-	dir := t.TempDir()
-	prev := calendarsDir
-	calendarsDir = dir
-	t.Cleanup(func() { calendarsDir = prev })
-
-	ics := "BEGIN:VCALENDAR\r\nVERSION:2.0\r\nBEGIN:VEVENT\r\nUID:1\r\nSUMMARY:95,6kg\r\nDTSTART;VALUE=DATE:20261003\r\nEND:VEVENT\r\nEND:VCALENDAR\r\n"
-	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if u, p, _ := r.BasicAuth(); u != "me" || p != "secret" {
-			w.WriteHeader(http.StatusUnauthorized)
-			return
-		}
-		switch {
-		case r.Method == "PROPFIND" && r.URL.Path == "/dav/calendars/me/":
-			w.WriteHeader(http.StatusMultiStatus)
-			io.WriteString(w, `<?xml version="1.0"?>
-<d:multistatus xmlns:d="DAV:" xmlns:cal="urn:ietf:params:xml:ns:caldav">
- <d:response><d:href>/dav/calendars/me/</d:href><d:propstat><d:prop><d:resourcetype><d:collection/></d:resourcetype></d:prop><d:status>HTTP/1.1 200 OK</d:status></d:propstat></d:response>
- <d:response><d:href>/dav/calendars/me/gewicht/</d:href><d:propstat><d:prop><d:displayname>Gewicht</d:displayname><d:resourcetype><d:collection/><cal:calendar/></d:resourcetype></d:prop><d:status>HTTP/1.1 200 OK</d:status></d:propstat></d:response>
- <d:response><d:href>/dav/calendars/me/broken/</d:href><d:propstat><d:prop><d:displayname>Broken/Name</d:displayname><d:resourcetype><d:collection/><cal:calendar/></d:resourcetype></d:prop><d:status>HTTP/1.1 200 OK</d:status></d:propstat></d:response>
- <d:response><d:href>/dav/calendars/me/inbox/</d:href><d:propstat><d:prop><d:resourcetype><d:collection/><cal:schedule-inbox/></d:resourcetype></d:prop><d:status>HTTP/1.1 200 OK</d:status></d:propstat></d:response>
-</d:multistatus>`)
-		case r.Method == http.MethodGet && r.URL.Path == "/dav/calendars/me/gewicht/" && r.URL.RawQuery == "export":
-			io.WriteString(w, ics)
-		case r.Method == http.MethodGet && r.URL.Path == "/dav/calendars/me/broken/":
-			io.WriteString(w, "<html>login</html>")
-		default:
-			http.NotFound(w, r)
-		}
-	}))
-	defer srv.Close()
-
-	// An existing file must survive a broken download.
-	if err := os.WriteFile(filepath.Join(dir, "Broken_Name.ics"), []byte("old"), 0644); err != nil {
-		t.Fatal(err)
-	}
-	results, err := syncCalendars(calendarSettings{CaldavURL: srv.URL + "/dav/calendars/me", CaldavUser: "me", CaldavPass: "secret"})
-	if err != nil {
-		t.Fatal(err)
-	}
-	if len(results) != 2 || results["Gewicht"].Error != "" || results["Broken_Name"].Error == "" {
-		t.Fatalf("results = %+v", results)
-	}
-	if got, _ := os.ReadFile(filepath.Join(dir, "Gewicht.ics")); string(got) != ics {
-		t.Fatalf("Gewicht.ics = %q", got)
-	}
-	if got, _ := os.ReadFile(filepath.Join(dir, "Broken_Name.ics")); string(got) != "old" {
-		t.Fatalf("broken download replaced the file: %q", got)
-	}
-
-	if _, err := syncCalendars(calendarSettings{CaldavURL: srv.URL + "/dav/calendars/me/", CaldavUser: "me", CaldavPass: "wrong"}); err == nil || !strings.Contains(err.Error(), "authentication") {
-		t.Fatalf("wrong password: err = %v", err)
-	}
-}
-
-func TestHasDotSegment(t *testing.T) {
-	for p, want := range map[string]bool{
-		"/Calendars/.page-settings": true,
-		"/.auth-key":                true,
-		"/a/.hidden/b.txt":          true,
-		"/Calendars/Personal.ics":   false,
-		"/a/b.c/":                   false,
-		"/a/../.auth-key":           true,
-		"/":                         false,
-	} {
-		if got := hasDotSegment(p); got != want {
-			t.Errorf("hasDotSegment(%q) = %v, want %v", p, got, want)
-		}
-	}
-}

calendarpage.go

@@ -1,116 +0,0 @@
-package main
-
-import (
-	"bytes"
-	"html/template"
-	"log"
-	"net/http"
-	"os"
-	"path/filepath"
-	"sort"
-	"strconv"
-	"strings"
-	"time"
-)
-
-func init() {
-	pageTypeHandlers = append(pageTypeHandlers, &calendarsHandler{})
-}
-
-// calendarsHandler renders folders whose .page-settings declares
-// type = calendars: the maintenance table and the sync status. Markdown
-// content and the listing stay visible, as in the fitness folder.
-type calendarsHandler struct{}
-
-func (c *calendarsHandler) redirect(root, fsPath, urlPath string, r *http.Request) (string, bool) {
-	return "", false
-}
-
-func (c *calendarsHandler) handle(root, fsPath, urlPath string, r *http.Request) *specialPage {
-	s := readPageSettings(fsPath)
-	if s == nil || s.Type != "calendars" {
-		return nil
-	}
-	return &specialPage{Content: renderCalendarsPage(fsPath), SuppressTOC: true}
-}
-
-type calFileRow struct {
-	Name    string
-	Roles   string
-	Events  string
-	Updated string // file modification time
-	Error   string // last sync or parse error
-}
-
-type calPageData struct {
-	HasMaintenance bool
-	Maintenance    []maintSeriesRow
-	Calendars      []calFileRow
-	// Sync is only shown for the configured calendars folder.
-	IsSyncDir   bool
-	SyncEnabled bool
-	LastRun     string
-	LastError   string
-}
-
-var calPageTmpl = template.Must(template.ParseFS(assets, "assets/calendar/page.html"))
-
-func renderCalendarsPage(dir string) template.HTML {
-	s := readCalendarSettings(dir)
-	data := calPageData{
-		HasMaintenance: len(s.Maintenance) > 0,
-		Maintenance:    maintenanceSeries(dir, s.Maintenance, time.Now()),
-		IsSyncDir:      calendarsDir != "" && dir == calendarsDir,
-		SyncEnabled:    s.CaldavURL != "",
-	}
-
-	var results map[string]calSyncResult
-	if data.IsSyncDir {
-		var lastRun time.Time
-		lastRun, data.LastError, results = calSyncSnapshot()
-		if !lastRun.IsZero() {
-			data.LastRun = lastRun.Format("2006-01-02 15:04")
-		}
-	}
-
-	roles := map[string][]string{}
-	for role, names := range map[string][]string{"diary": s.Diary, "weight": s.Weight, "maintenance": s.Maintenance} {
-		for _, n := range names {
-			roles[n] = append(roles[n], role)
-		}
-	}
-	entries, _ := os.ReadDir(dir)
-	for _, e := range entries {
-		name := e.Name()
-		if e.IsDir() || strings.HasPrefix(name, ".") || !strings.EqualFold(filepath.Ext(name), ".ics") {
-			continue
-		}
-		name = strings.TrimSuffix(name, filepath.Ext(name))
-		sort.Strings(roles[name])
-		row := calFileRow{Name: name, Roles: strings.Join(roles[name], ", "), Error: results[name].Error}
-		if info, err := e.Info(); err == nil {
-			row.Updated = info.ModTime().Format("2006-01-02 15:04")
-		}
-		if f := loadCalendar(filepath.Join(dir, e.Name())); f != nil {
-			row.Events = strconv.Itoa(f.events)
-		} else if row.Error == "" {
-			row.Error = "cannot parse file"
-		}
-		data.Calendars = append(data.Calendars, row)
-		delete(results, name)
-	}
-	// Calendars whose download failed before a file ever existed.
-	for name, r := range results {
-		if r.Error != "" {
-			data.Calendars = append(data.Calendars, calFileRow{Name: name, Error: r.Error})
-		}
-	}
-	sort.SliceStable(data.Calendars, func(i, j int) bool { return data.Calendars[i].Name < data.Calendars[j].Name })
-
-	var buf bytes.Buffer
-	if err := calPageTmpl.Execute(&buf, data); err != nil {
-		log.Printf("calendars page template: %v", err)
-		return ""
-	}
-	return template.HTML(buf.String())
-}

calsync.go

@@ -1,296 +0,0 @@
-package main
-
-import (
-	"bytes"
-	"encoding/xml"
-	"errors"
-	"fmt"
-	"io"
-	"log"
-	"net/http"
-	"net/url"
-	"os"
-	"path"
-	"strings"
-	"sync"
-	"time"
-)
-
-// The calendar sync mirrors every calendar of a CalDAV calendar home (e.g.
-// Nextcloud's /remote.php/dav/calendars/<user>/) into calendarsDir as
-// <display name>.ics. It runs in the background only: page renders read the
-// local files and never touch the network. A failed run leaves the previous
-// files in place.
-
-// calSyncMaxBody bounds a single calendar download.
-const calSyncMaxBody = 64 << 20
-
-var calSyncClient = &http.Client{Timeout: 60 * time.Second}
-
-// calSyncResult is the outcome of the last run for one calendar.
-type calSyncResult struct {
-	Updated time.Time // last successful download
-	Error   string
-}
-
-var calSync struct {
-	run sync.Mutex // serializes runs
-
-	mu        sync.Mutex // guards the fields below
-	lastRun   time.Time
-	lastError string // config/discovery error of the last run
-	results   map[string]calSyncResult
-}
-
-// startCalendarSync checks the settings once a minute and syncs when the
-// interval since the last run has passed. The first check happens right
-// away. Settings are read every time, so enabling the sync or changing the
-// interval needs no restart.
-func startCalendarSync() {
-	go func() {
-		for {
-			s := readCalendarSettings(calendarsDir)
-			if s.CaldavURL != "" {
-				calSync.mu.Lock()
-				last := calSync.lastRun
-				calSync.mu.Unlock()
-				if last.IsZero() || (s.SyncInterval > 0 && time.Since(last) >= s.SyncInterval) {
-					runCalendarSync()
-				}
-			}
-			time.Sleep(time.Minute)
-		}
-	}()
-}
-
-// runCalendarSync performs one sync run and records the outcome.
-func runCalendarSync() {
-	calSync.run.Lock()
-	defer calSync.run.Unlock()
-
-	results, err := syncCalendars(readCalendarSettings(calendarsDir))
-
-	calSync.mu.Lock()
-	defer calSync.mu.Unlock()
-	calSync.lastRun = time.Now()
-	calSync.lastError = ""
-	if err != nil {
-		calSync.lastError = err.Error()
-		log.Printf("calendar sync: %v", err)
-	}
-	if calSync.results == nil {
-		calSync.results = map[string]calSyncResult{}
-	}
-	for name, r := range results {
-		prev := calSync.results[name]
-		if r.Updated.IsZero() {
-			r.Updated = prev.Updated
-		}
-		calSync.results[name] = r
-		if r.Error != "" {
-			log.Printf("calendar sync %s: %s", name, r.Error)
-		}
-	}
-}
-
-// calSyncSnapshot returns a copy of the sync status for display.
-func calSyncSnapshot() (lastRun time.Time, lastError string, results map[string]calSyncResult) {
-	calSync.mu.Lock()
-	defer calSync.mu.Unlock()
-	results = make(map[string]calSyncResult, len(calSync.results))
-	for k, v := range calSync.results {
-		results[k] = v
-	}
-	return calSync.lastRun, calSync.lastError, results
-}
-
-// handleCalendarSync runs a sync now (POST ?calsync on the calendars page)
-// and returns to the page.
-func (h *handler) handleCalendarSync(w http.ResponseWriter, r *http.Request, urlPath, fsPath string) {
-	if calendarsDir == "" || fsPath != calendarsDir {
-		http.Error(w, "not the calendars folder", http.StatusBadRequest)
-		return
-	}
-	if readCalendarSettings(calendarsDir).CaldavURL == "" {
-		http.Error(w, "sync is not configured (caldav-url)", http.StatusBadRequest)
-		return
-	}
-	runCalendarSync()
-	http.Redirect(w, r, urlPath, http.StatusSeeOther)
-}
-
-// syncCalendars downloads every calendar of the calendar home. The returned
-// map has one entry per calendar that was attempted; err is set when nothing
-// could be attempted (bad settings, discovery failed).
-func syncCalendars(s calendarSettings) (map[string]calSyncResult, error) {
-	home, err := url.Parse(s.CaldavURL)
-	if err != nil || (home.Scheme != "http" && home.Scheme != "https") {
-		return nil, fmt.Errorf("invalid caldav-url %q", s.CaldavURL)
-	}
-	if !strings.HasSuffix(home.Path, "/") {
-		home.Path += "/"
-	}
-	cals, err := davDiscoverCalendars(home, s)
-	if err != nil {
-		return nil, err
-	}
-
-	results := map[string]calSyncResult{}
-	used := map[string]bool{}
-	for _, c := range cals {
-		name := calendarFileName(c.name, c.href)
-		if used[strings.ToLower(name)] {
-			name += " (" + path.Base(strings.TrimSuffix(c.href, "/")) + ")"
-		}
-		used[strings.ToLower(name)] = true
-
-		if err := syncOneCalendar(home, c.href, name, s); err != nil {
-			results[name] = calSyncResult{Error: err.Error()}
-			continue
-		}
-		results[name] = calSyncResult{Updated: time.Now()}
-	}
-	return results, nil
-}
-
-// syncOneCalendar downloads one calendar via Nextcloud's ?export and writes
-// it when the content changed. Invalid downloads (HTML error pages, broken
-// iCalendar) never replace the existing file.
-func syncOneCalendar(home *url.URL, href, name string, s calendarSettings) error {
-	u, err := home.Parse(href)
-	if err != nil {
-		return err
-	}
-	u.RawQuery = "export"
-	req, err := http.NewRequest(http.MethodGet, u.String(), nil)
-	if err != nil {
-		return err
-	}
-	req.SetBasicAuth(s.CaldavUser, s.CaldavPass)
-	req.Header.Set("Accept", "text/calendar")
-	resp, err := calSyncClient.Do(req)
-	if err != nil {
-		return err
-	}
-	defer resp.Body.Close()
-	if resp.StatusCode != http.StatusOK {
-		return fmt.Errorf("download: %s", resp.Status)
-	}
-	data, err := io.ReadAll(io.LimitReader(resp.Body, calSyncMaxBody+1))
-	if err != nil {
-		return err
-	}
-	if len(data) > calSyncMaxBody {
-		return errors.New("download: calendar larger than 64 MB")
-	}
-	if _, err := parseCalendar(name+".ics", data); err != nil {
-		return fmt.Errorf("invalid calendar data: %v", err)
-	}
-
-	p := calendarPath(calendarsDir, name)
-	if p == "" {
-		return fmt.Errorf("unusable file name %q", name)
-	}
-	if old, err := os.ReadFile(p); err == nil && bytes.Equal(old, data) {
-		return nil
-	}
-	if err := os.MkdirAll(calendarsDir, 0755); err != nil {
-		return err
-	}
-	return writeFileAtomic(p, data, 0644)
-}
-
-// calendarFileName turns a display name into a safe file basename. Falls back
-// to the last segment of the calendar's href.
-func calendarFileName(display, href string) string {
-	clean := strings.Map(func(r rune) rune {
-		if r < 0x20 || strings.ContainsRune(`/\:*?"<>|`, r) {
-			return '_'
-		}
-		return r
-	}, display)
-	clean = strings.TrimLeft(strings.TrimSpace(clean), ".")
-	if clean == "" {
-		clean = strings.TrimLeft(path.Base(strings.TrimSuffix(href, "/")), ".")
-	}
-	if clean == "" {
-		clean = "calendar"
-	}
-	return clean
-}
-
-// === Discovery ===
-
-type davCalendar struct {
-	href string
-	name string
-}
-
-const davPropfindBody = `<?xml version="1.0" encoding="utf-8"?>
-<d:propfind xmlns:d="DAV:"><d:prop><d:displayname/><d:resourcetype/></d:prop></d:propfind>`
-
-type davMultistatus struct {
-	Responses []struct {
-		Href      string `xml:"DAV: href"`
-		Propstats []struct {
-			Status string `xml:"DAV: status"`
-			Prop   struct {
-				DisplayName  string `xml:"DAV: displayname"`
-				ResourceType struct {
-					Types []struct {
-						XMLName xml.Name
-					} `xml:",any"`
-				} `xml:"DAV: resourcetype"`
-			} `xml:"DAV: prop"`
-		} `xml:"DAV: propstat"`
-	} `xml:"DAV: response"`
-}
-
-// davDiscoverCalendars lists the calendar collections directly below home
-// with one PROPFIND (Depth 1).
-func davDiscoverCalendars(home *url.URL, s calendarSettings) ([]davCalendar, error) {
-	req, err := http.NewRequest("PROPFIND", home.String(), strings.NewReader(davPropfindBody))
-	if err != nil {
-		return nil, err
-	}
-	req.SetBasicAuth(s.CaldavUser, s.CaldavPass)
-	req.Header.Set("Depth", "1")
-	req.Header.Set("Content-Type", "application/xml; charset=utf-8")
-	resp, err := calSyncClient.Do(req)
-	if err != nil {
-		return nil, fmt.Errorf("discovery: %v", err)
-	}
-	defer resp.Body.Close()
-	if resp.StatusCode == http.StatusUnauthorized {
-		return nil, errors.New("discovery: authentication failed (check caldav-user / caldav-pass)")
-	}
-	if resp.StatusCode != http.StatusMultiStatus {
-		return nil, fmt.Errorf("discovery: %s", resp.Status)
-	}
-	var ms davMultistatus
-	if err := xml.NewDecoder(io.LimitReader(resp.Body, calSyncMaxBody)).Decode(&ms); err != nil {
-		return nil, fmt.Errorf("discovery: %v", err)
-	}
-
-	var out []davCalendar
-	for _, r := range ms.Responses {
-		for _, ps := range r.Propstats {
-			if !strings.Contains(ps.Status, " 200 ") {
-				continue
-			}
-			isCalendar := false
-			for _, t := range ps.Prop.ResourceType.Types {
-				if t.XMLName.Space == "urn:ietf:params:xml:ns:caldav" && t.XMLName.Local == "calendar" {
-					isCalendar = true
-				}
-			}
-			if isCalendar {
-				out = append(out, davCalendar{href: r.Href, name: strings.TrimSpace(ps.Prop.DisplayName)})
-			}
-		}
-	}
-	if len(out) == 0 {
-		return nil, errors.New("discovery: no calendars found at caldav-url")
-	}
-	return out, nil
-}

canvas.go

@@ -0,0 +1,699 @@
+package main
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"html"
+	"html/template"
+	"io"
+	"log"
+	"net/http"
+	"net/url"
+	"os"
+	"path"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strings"
+)
+
+// JSON Canvas (https://jsoncanvas.org/spec/1.0/) support.
+//
+// A canvas is a `<Name>.canvas` file sitting in a page folder, addressed as an
+// alternative *view* of that page rather than as a standalone file:
+//
+//	/Topics/Ideas/?canvas=Architecture      the canvas view
+//	/Topics/Ideas/Architecture.canvas       302 -> the line above
+//	/Topics/Ideas/Architecture.canvas?raw   the file bytes
+//
+// Routing through the folder keeps the page's identity (breadcrumb, tree,
+// header actions) and lets every canvas in a folder render as a tab strip above
+// the page content. The redirect mirrors how diary.go collapses its virtual
+// month/day URLs onto one canonical form.
+//
+// The server owns the format: it parses and validates on every read and write,
+// re-marshals from its own structs on save, and never writes bytes it has not
+// round-tripped through canvasDoc. Keys it does not model are dropped rather
+// than preserved — this wiki is the only writer.
+
+const canvasExt = ".canvas"
+
+// canvasMaxBytes caps a save payload. A canvas is coordinates and prose; a
+// megabyte is already far past any hand-built diagram and well short of
+// anything that could pressure the NAS.
+const canvasMaxBytes = 4 << 20
+
+// canvasRenderMaxBytes caps a /_canvas/render body. Only one node's content
+// travels at a time.
+const canvasRenderMaxBytes = 1 << 20
+
+// Structural caps. These exist so a looping client cannot grow a file until it
+// stops loading, not because the format has limits.
+const (
+	canvasMaxNodes = 5000
+	canvasMaxEdges = 10000
+	canvasMaxCoord = 1 << 20
+)
+
+// canvasNameRe restricts a ?canvas= value to a single safe path component: the
+// name is joined onto the folder path, so separators, dot-segments, control
+// characters, and leading dots (which would create a hidden file the listing
+// filters away) must all be rejected before the filesystem sees it.
+var canvasNameRe = regexp.MustCompile(`^[^./\\\x00-\x1f][^/\\\x00-\x1f]{0,99}$`)
+
+// canvasHexRe matches the hex form of a canvasColor. The spec also allows the
+// preset digits "1".."6"; see validCanvasColor.
+var canvasHexRe = regexp.MustCompile(`^#([0-9a-fA-F]{3}|[0-9a-fA-F]{6})$`)
+
+// Node types defined by the spec.
+const (
+	canvasNodeText  = "text"
+	canvasNodeFile  = "file"
+	canvasNodeLink  = "link"
+	canvasNodeGroup = "group"
+)
+
+// canvasDoc is a whole `.canvas` file. Both arrays are optional per the spec,
+// so an empty document marshals to `{}`.
+type canvasDoc struct {
+	Nodes []canvasNode `json:"nodes,omitempty"`
+	Edges []canvasEdge `json:"edges,omitempty"`
+}
+
+// canvasNode carries every node variant in one struct. The spec's four types
+// share six required attributes and add one to three of their own, so a flat
+// struct with omitempty round-trips all of them without the ceremony of a
+// custom unmarshaller; validate() enforces which extras a given Type may use.
+type canvasNode struct {
+	ID     string `json:"id"`
+	Type   string `json:"type"`
+	X      int    `json:"x"`
+	Y      int    `json:"y"`
+	Width  int    `json:"width"`
+	Height int    `json:"height"`
+	Color  string `json:"color,omitempty"`
+
+	Text            string `json:"text,omitempty"`            // type=text
+	File            string `json:"file,omitempty"`            // type=file
+	Subpath         string `json:"subpath,omitempty"`         // type=file
+	URL             string `json:"url,omitempty"`             // type=link
+	Label           string `json:"label,omitempty"`           // type=group
+	Background      string `json:"background,omitempty"`      // type=group
+	BackgroundStyle string `json:"backgroundStyle,omitempty"` // type=group
+}
+
+type canvasEdge struct {
+	ID       string `json:"id"`
+	FromNode string `json:"fromNode"`
+	FromSide string `json:"fromSide,omitempty"`
+	FromEnd  string `json:"fromEnd,omitempty"` // defaults to "none"
+	ToNode   string `json:"toNode"`
+	ToSide   string `json:"toSide,omitempty"`
+	ToEnd    string `json:"toEnd,omitempty"` // defaults to "arrow"
+	Color    string `json:"color,omitempty"`
+	Label    string `json:"label,omitempty"`
+}
+
+// canvasRef is one entry in the page's view switcher.
+type canvasRef struct {
+	Name   string
+	URL    string
+	Active bool
+}
+
+// canvasPayload is the single blob inlined into the canvas page. Shipping the
+// document *and* its server-rendered node HTML together means opening a canvas
+// costs exactly one request no matter how many nodes it holds — the obvious
+// alternative (one content request per node on load) fans out badly over the
+// mobile/VPN path.
+type canvasPayload struct {
+	Name     string                   `json:"name"`
+	PostURL  string                   `json:"postUrl"`
+	Hash     string                   `json:"hash"`
+	Doc      *canvasDoc               `json:"doc"`
+	Rendered map[string]template.HTML `json:"rendered"`
+}
+
+// --- parsing and validation ---
+
+// parseCanvas unmarshals and validates raw canvas bytes. Unknown keys are
+// ignored rather than rejected so a hand-edited file with a stray attribute
+// still opens; they are dropped on the next save.
+func parseCanvas(raw []byte) (*canvasDoc, error) {
+	doc := &canvasDoc{}
+	if len(strings.TrimSpace(string(raw))) == 0 {
+		return doc, nil
+	}
+	if err := json.Unmarshal(raw, doc); err != nil {
+		return nil, fmt.Errorf("invalid JSON: %w", err)
+	}
+	if err := doc.validate(); err != nil {
+		return nil, err
+	}
+	return doc, nil
+}
+
+// validate rejects anything that would render as a broken or invisible canvas.
+// It runs on read as well as write: a file edited by hand outside the app gets
+// the same diagnosis the editor would give, naming the offending node.
+func (c *canvasDoc) validate() error {
+	if len(c.Nodes) > canvasMaxNodes {
+		return fmt.Errorf("too many nodes (%d, max %d)", len(c.Nodes), canvasMaxNodes)
+	}
+	if len(c.Edges) > canvasMaxEdges {
+		return fmt.Errorf("too many edges (%d, max %d)", len(c.Edges), canvasMaxEdges)
+	}
+
+	ids := make(map[string]bool, len(c.Nodes))
+	for i := range c.Nodes {
+		n := &c.Nodes[i]
+		if n.ID == "" {
+			return fmt.Errorf("node %d: missing id", i)
+		}
+		if ids[n.ID] {
+			return fmt.Errorf("duplicate node id %q", n.ID)
+		}
+		ids[n.ID] = true
+
+		switch n.Type {
+		case canvasNodeText:
+			// An empty text node is a node the user just created and has not
+			// typed into yet, so emptiness is allowed here even though the spec
+			// calls `text` required. A missing *file* or *url*, by contrast, is
+			// a node that can never render anything.
+		case canvasNodeFile:
+			if n.File == "" {
+				return fmt.Errorf("node %q: file node has no file", n.ID)
+			}
+			if n.Subpath != "" && !strings.HasPrefix(n.Subpath, "#") {
+				return fmt.Errorf("node %q: subpath must start with #", n.ID)
+			}
+		case canvasNodeLink:
+			if n.URL == "" {
+				return fmt.Errorf("node %q: link node has no url", n.ID)
+			}
+		case canvasNodeGroup:
+			if n.BackgroundStyle != "" {
+				switch n.BackgroundStyle {
+				case "cover", "ratio", "repeat":
+				default:
+					return fmt.Errorf("node %q: bad backgroundStyle %q", n.ID, n.BackgroundStyle)
+				}
+			}
+		case "":
+			return fmt.Errorf("node %q: missing type", n.ID)
+		default:
+			return fmt.Errorf("node %q: unknown type %q", n.ID, n.Type)
+		}
+
+		if n.Width <= 0 || n.Height <= 0 {
+			return fmt.Errorf("node %q: width and height must be positive", n.ID)
+		}
+		if n.Width > canvasMaxCoord || n.Height > canvasMaxCoord ||
+			abs(n.X) > canvasMaxCoord || abs(n.Y) > canvasMaxCoord {
+			return fmt.Errorf("node %q: coordinates out of range", n.ID)
+		}
+		if !validCanvasColor(n.Color) {
+			return fmt.Errorf("node %q: bad color %q", n.ID, n.Color)
+		}
+	}
+
+	edgeIDs := make(map[string]bool, len(c.Edges))
+	for i := range c.Edges {
+		e := &c.Edges[i]
+		if e.ID == "" {
+			return fmt.Errorf("edge %d: missing id", i)
+		}
+		if edgeIDs[e.ID] {
+			return fmt.Errorf("duplicate edge id %q", e.ID)
+		}
+		edgeIDs[e.ID] = true
+		if !ids[e.FromNode] {
+			return fmt.Errorf("edge %q: fromNode %q does not exist", e.ID, e.FromNode)
+		}
+		if !ids[e.ToNode] {
+			return fmt.Errorf("edge %q: toNode %q does not exist", e.ID, e.ToNode)
+		}
+		if !validCanvasSide(e.FromSide) {
+			return fmt.Errorf("edge %q: bad fromSide %q", e.ID, e.FromSide)
+		}
+		if !validCanvasSide(e.ToSide) {
+			return fmt.Errorf("edge %q: bad toSide %q", e.ID, e.ToSide)
+		}
+		if !validCanvasEnd(e.FromEnd) {
+			return fmt.Errorf("edge %q: bad fromEnd %q", e.ID, e.FromEnd)
+		}
+		if !validCanvasEnd(e.ToEnd) {
+			return fmt.Errorf("edge %q: bad toEnd %q", e.ID, e.ToEnd)
+		}
+		if !validCanvasColor(e.Color) {
+			return fmt.Errorf("edge %q: bad color %q", e.ID, e.Color)
+		}
+	}
+	return nil
+}
+
+func abs(n int) int {
+	if n < 0 {
+		return -n
+	}
+	return n
+}
+
+// validCanvasColor accepts an absent color, a preset digit "1".."6" (red,
+// orange, yellow, green, cyan, purple), or a hex string.
+func validCanvasColor(c string) bool {
+	switch c {
+	case "", "1", "2", "3", "4", "5", "6":
+		return true
+	}
+	return canvasHexRe.MatchString(c)
+}
+
+func validCanvasSide(s string) bool {
+	switch s {
+	case "", "top", "right", "bottom", "left":
+		return true
+	}
+	return false
+}
+
+func validCanvasEnd(e string) bool {
+	switch e {
+	case "", "none", "arrow":
+		return true
+	}
+	return false
+}
+
+// canvasHash is the conflict token exchanged with the client. It covers the
+// exact bytes on disk, so any edit made outside this editor invalidates it.
+func canvasHash(raw []byte) string {
+	sum := sha256.Sum256(raw)
+	return hex.EncodeToString(sum[:])[:16]
+}
+
+// --- paths and discovery ---
+
+func canvasPath(fsPath, name string) string {
+	return filepath.Join(fsPath, name+canvasExt)
+}
+
+// canvasBackupPath is the previous-contents copy kept beside a canvas. The dot
+// prefix keeps it out of the file listing and the search index.
+func canvasBackupPath(fsPath, name string) string {
+	return filepath.Join(fsPath, "."+name+canvasExt+".bak")
+}
+
+// canvasURL builds the canonical view URL for a canvas in the folder at urlPath.
+func canvasURL(urlPath, name string) string {
+	if !strings.HasSuffix(urlPath, "/") {
+		urlPath += "/"
+	}
+	return urlPath + "?canvas=" + url.QueryEscape(name)
+}
+
+// canvasViewURL maps a direct `/A/B/Name.canvas` request onto the canonical
+// `/A/B/?canvas=Name` form. Segments are re-encoded because urlPath arrives
+// already percent-decoded.
+func canvasViewURL(urlPath string) (string, bool) {
+	base := path.Base(urlPath)
+	name := strings.TrimSuffix(base, canvasExt)
+	if name == "" || name == base || !canvasNameRe.MatchString(name) {
+		return "", false
+	}
+	return canvasURL(fileURL(strings.Trim(path.Dir(urlPath), "/")), name), true
+}
+
+// listCanvases returns the canvases in a folder as view-switcher tabs, sorted
+// case-insensitively by name. active marks the one currently being viewed.
+func listCanvases(fsPath, urlPath, active string) []canvasRef {
+	entries, err := os.ReadDir(fsPath)
+	if err != nil {
+		return nil
+	}
+	var refs []canvasRef
+	for _, e := range entries {
+		name := e.Name()
+		if e.IsDir() || strings.HasPrefix(name, ".") || !strings.HasSuffix(name, canvasExt) {
+			continue
+		}
+		base := strings.TrimSuffix(name, canvasExt)
+		if !canvasNameRe.MatchString(base) {
+			continue
+		}
+		refs = append(refs, canvasRef{
+			Name:   base,
+			URL:    canvasURL(urlPath, base),
+			Active: base == active,
+		})
+	}
+	sort.Slice(refs, func(i, j int) bool {
+		return strings.ToLower(refs[i].Name) < strings.ToLower(refs[j].Name)
+	})
+	return refs
+}
+
+// isCanvasFile reports whether a listing entry is a canvas. Used to keep
+// canvases out of the Files listing — they are surfaced as tabs above the
+// content instead, the same reasoning that hides index.md.
+func isCanvasFile(name string) bool {
+	return strings.HasSuffix(name, canvasExt)
+}
+
+// --- server-side node rendering ---
+
+// prerenderNodes renders every node whose content the server owns, keyed by
+// node id. Link and group nodes are built entirely in the browser and are
+// absent from the map.
+func (h *handler) prerenderNodes(c *canvasDoc) map[string]template.HTML {
+	out := make(map[string]template.HTML, len(c.Nodes))
+	for i := range c.Nodes {
+		n := &c.Nodes[i]
+		switch n.Type {
+		case canvasNodeText:
+			out[n.ID] = renderMarkdown([]byte(n.Text))
+		case canvasNodeFile:
+			out[n.ID] = h.renderFileNode(n.File, n.Subpath)
+		}
+	}
+	return out
+}
+
+// renderFileNode renders a file node's transclusion. Markdown is rendered
+// through the shared goldmark instance so wikilinks, embeds, tables, and task
+// checkboxes behave exactly as they do on a page; media gets a player or an
+// <img> pointed at the existing thumbnail endpoint; anything else degrades to
+// a link. A missing target renders visibly broken rather than blank.
+func (h *handler) renderFileNode(file, subpath string) template.HTML {
+	target := "/" + strings.Trim(file, "/")
+	fsPath := filepath.Join(h.root, filepath.FromSlash(strings.TrimPrefix(target, "/")))
+	if rel, err := filepath.Rel(h.root, fsPath); err != nil || strings.HasPrefix(rel, "..") {
+		return canvasBrokenRef(file, "outside the wiki")
+	}
+
+	info, err := os.Stat(fsPath)
+	if err != nil {
+		return canvasBrokenRef(file, "not found")
+	}
+	if info.IsDir() {
+		// A folder is a page; transclude its markdown.
+		fsPath = filepath.Join(fsPath, "index.md")
+		if _, err := os.Stat(fsPath); err != nil {
+			return canvasBrokenRef(file, "page has no content")
+		}
+		return h.renderMarkdownFile(fsPath, file, subpath)
+	}
+
+	name := path.Base(target)
+	href := html.EscapeString(fileURL(strings.TrimPrefix(target, "/")))
+	switch {
+	case isImageFile(name):
+		return template.HTML(`<a class="canvas-media" href="` + href + `"><img src="` +
+			html.EscapeString(thumbURL(fileURL(strings.TrimPrefix(target, "/")), 800)) + `" alt="" loading="lazy"></a>`)
+	case isVideoFile(name):
+		return template.HTML(`<video class="canvas-media" controls preload="metadata" src="` + href + `"></video>`)
+	case strings.EqualFold(path.Ext(name), ".pdf"):
+		return template.HTML(`<embed class="canvas-media" type="application/pdf" src="` + href + `">`)
+	case strings.EqualFold(path.Ext(name), ".md"):
+		return h.renderMarkdownFile(fsPath, file, subpath)
+	default:
+		return template.HTML(`<p class="canvas-file-fallback"><a href="` + href + `">` +
+			html.EscapeString(name) + `</a></p>`)
+	}
+}
+
+// renderMarkdownFile renders a markdown file, optionally narrowed to the
+// section named by subpath (`#Heading`). The narrowing reuses the same section
+// machinery the page editor uses, so a heading spans its subsections.
+func (h *handler) renderMarkdownFile(fsPath, file, subpath string) template.HTML {
+	raw, err := os.ReadFile(fsPath)
+	if err != nil {
+		return canvasBrokenRef(file, "unreadable")
+	}
+	if subpath != "" {
+		section, ok := canvasSubpathSection(raw, subpath)
+		if !ok {
+			return canvasBrokenRef(file+subpath, "no such heading")
+		}
+		raw = section
+	}
+	return renderMarkdown(raw)
+}
+
+// canvasSubpathSection narrows raw markdown to the section whose heading
+// matches subpath. The match accepts either the heading text (what a human
+// types) or goldmark's generated anchor id (what a copied link contains).
+func canvasSubpathSection(raw []byte, subpath string) ([]byte, bool) {
+	want := strings.TrimSpace(strings.TrimPrefix(subpath, "#"))
+	if want == "" {
+		return raw, true
+	}
+	sections := splitSections(raw)
+	ids := headingIDs(raw)
+	for i := 1; i < len(sections); i++ {
+		_, text := sectionHeading(sections[i])
+		id := ""
+		if i-1 < len(ids) {
+			id = ids[i-1]
+		}
+		if strings.EqualFold(text, want) || id == want {
+			return joinSections(sections[i:secionSpanEnd(sections, i)]), true
+		}
+	}
+	return nil, false
+}
+
+func canvasBrokenRef(target, reason string) template.HTML {
+	return template.HTML(`<p class="canvas-broken">` + html.EscapeString(target) +
+		` <span class="muted">(` + html.EscapeString(reason) + `)</span></p>`)
+}
+
+// --- request handlers ---
+
+// serveCanvas renders the canvas view of a page. Reached from serveDir when
+// the request carries ?canvas=<name>.
+func (h *handler) serveCanvas(w http.ResponseWriter, r *http.Request, urlPath, fsPath, name string) {
+	if !canvasNameRe.MatchString(name) {
+		http.Error(w, "bad canvas name", http.StatusBadRequest)
+		return
+	}
+	raw, err := os.ReadFile(canvasPath(fsPath, name))
+	if err != nil {
+		if os.IsNotExist(err) {
+			http.NotFound(w, r)
+			return
+		}
+		http.Error(w, "read failed: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	data := pageData{
+		Title:        name + " — " + pageTitle(urlPath),
+		CanEdit:      true,
+		IsRoot:       urlPath == "/",
+		SectionIndex: -1,
+		InsertBefore: -1,
+		PostURL:      urlPath,
+		ActiveCanvas: name,
+		Canvases:     listCanvases(fsPath, urlPath, name),
+	}
+
+	// A parse failure is reported in-page rather than as a bare error: the file
+	// is hand-editable, so the user needs to see which node is wrong and still
+	// reach the raw bytes.
+	doc, parseErr := parseCanvas(raw)
+	if parseErr != nil {
+		data.CanvasError = parseErr.Error()
+	} else {
+		payload := canvasPayload{
+			Name:     name,
+			PostURL:  urlPath,
+			Hash:     canvasHash(raw),
+			Doc:      doc,
+			Rendered: h.prerenderNodes(doc),
+		}
+		// encoding/json escapes <, >, & and the U+2028/U+2029 line separators,
+		// so the result is safe to inline verbatim in a <script> block.
+		blob, err := json.Marshal(payload)
+		if err != nil {
+			http.Error(w, "encode failed: "+err.Error(), http.StatusInternalServerError)
+			return
+		}
+		data.CanvasJSON = template.JS(blob)
+	}
+
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	data.RenderMS = elapsedMS(r)
+	if err := canvasTmpl.ExecuteTemplate(w, "layout", data); err != nil {
+		log.Printf("template error: %v", err)
+	}
+}
+
+// handleCanvasPost dispatches every POST carrying ?canvas=. It is checked
+// before the page-level delete/move actions in handlePost so `?canvas=X&delete`
+// removes the canvas rather than the whole page.
+func (h *handler) handleCanvasPost(w http.ResponseWriter, r *http.Request, urlPath, fsPath, name string) {
+	if !canvasNameRe.MatchString(name) {
+		http.Error(w, "bad canvas name", http.StatusBadRequest)
+		return
+	}
+	query := r.URL.Query()
+	switch {
+	case query.Has("create"):
+		h.handleCanvasCreate(w, r, urlPath, fsPath, name)
+	case query.Has("delete"):
+		h.handleCanvasDelete(w, r, urlPath, fsPath, name)
+	case query.Has("rename"):
+		h.handleCanvasRename(w, r, urlPath, fsPath, name, query.Get("rename"))
+	default:
+		h.handleCanvasSave(w, r, urlPath, fsPath, name)
+	}
+}
+
+// handleCanvasSave replaces a canvas with the posted document. The write is
+// gated on four checks in order — parse, validate, version, non-empty — so a
+// malformed or stale payload never reaches the file.
+func (h *handler) handleCanvasSave(w http.ResponseWriter, r *http.Request, urlPath, fsPath, name string) {
+	body, err := io.ReadAll(http.MaxBytesReader(w, r.Body, canvasMaxBytes))
+	if err != nil {
+		http.Error(w, "request too large or truncated", http.StatusBadRequest)
+		return
+	}
+	doc, err := parseCanvas(body)
+	if err != nil {
+		http.Error(w, "rejected: "+err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	p := canvasPath(fsPath, name)
+	current, readErr := os.ReadFile(p)
+	if readErr != nil && !os.IsNotExist(readErr) {
+		http.Error(w, "read failed: "+readErr.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	if want := r.Header.Get("X-Canvas-Version"); want != "" && want != canvasHash(current) {
+		http.Error(w, "the canvas changed since you opened it — reload to get the current version",
+			http.StatusConflict)
+		return
+	}
+
+	// A save must never blank a canvas. An empty document is indistinguishable
+	// from a client that lost its state, so emptying is only allowed when the
+	// caller says so explicitly — the same reasoning as the empty-content guard
+	// on page saves.
+	if len(doc.Nodes) == 0 && !r.URL.Query().Has("empty") {
+		if cur, err := parseCanvas(current); err == nil && len(cur.Nodes) > 0 {
+			http.Error(w, fmt.Sprintf("refusing to replace %d nodes with an empty canvas", len(cur.Nodes)),
+				http.StatusBadRequest)
+			return
+		}
+	}
+
+	out, err := json.MarshalIndent(doc, "", "\t")
+	if err != nil {
+		http.Error(w, "encode failed: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+	out = append(out, '\n')
+
+	if len(current) > 0 {
+		if err := writeFileAtomic(canvasBackupPath(fsPath, name), current, 0644); err != nil {
+			log.Printf("canvas backup %s: %v", p, err)
+		}
+	}
+	if err := writeFileAtomic(p, out, 0644); err != nil {
+		http.Error(w, "write failed: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	// Hand back the new token so the client can keep editing without reloading.
+	w.Header().Set("X-Canvas-Version", canvasHash(out))
+	w.WriteHeader(http.StatusNoContent)
+}
+
+func (h *handler) handleCanvasCreate(w http.ResponseWriter, r *http.Request, urlPath, fsPath, name string) {
+	if err := os.MkdirAll(fsPath, 0755); err != nil {
+		http.Error(w, "mkdir failed: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+	p := canvasPath(fsPath, name)
+	if _, err := os.Stat(p); err == nil {
+		http.Error(w, "a canvas with that name already exists", http.StatusConflict)
+		return
+	}
+	if err := writeFileAtomic(p, []byte("{}\n"), 0644); err != nil {
+		http.Error(w, "write failed: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+	http.Redirect(w, r, canvasURL(urlPath, name), http.StatusSeeOther)
+}
+
+func (h *handler) handleCanvasDelete(w http.ResponseWriter, r *http.Request, urlPath, fsPath, name string) {
+	if err := os.Remove(canvasPath(fsPath, name)); err != nil {
+		if os.IsNotExist(err) {
+			http.NotFound(w, r)
+			return
+		}
+		http.Error(w, "delete failed: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+	_ = os.Remove(canvasBackupPath(fsPath, name))
+	http.Redirect(w, r, urlPath, http.StatusSeeOther)
+}
+
+func (h *handler) handleCanvasRename(w http.ResponseWriter, r *http.Request, urlPath, fsPath, name, newName string) {
+	if !canvasNameRe.MatchString(newName) {
+		http.Error(w, "bad canvas name", http.StatusBadRequest)
+		return
+	}
+	if newName == name {
+		http.Redirect(w, r, canvasURL(urlPath, name), http.StatusSeeOther)
+		return
+	}
+	dst := canvasPath(fsPath, newName)
+	if _, err := os.Stat(dst); err == nil {
+		http.Error(w, "a canvas with that name already exists", http.StatusConflict)
+		return
+	}
+	if err := os.Rename(canvasPath(fsPath, name), dst); err != nil {
+		http.Error(w, "rename failed: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+	_ = os.Remove(canvasBackupPath(fsPath, name))
+	http.Redirect(w, r, canvasURL(urlPath, newName), http.StatusSeeOther)
+}
+
+// handleCanvasRender renders one node's content on demand. It is stateless and
+// takes the content in the request rather than reading it from the canvas file:
+// the node being re-rendered has just been edited in the browser and is not on
+// disk yet. Everything already on disk arrives pre-rendered with the page.
+func (h *handler) handleCanvasRender(w http.ResponseWriter, r *http.Request) {
+	if !h.checkAuth(w, r) {
+		return
+	}
+	if r.Method != http.MethodPost {
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+	r.Body = http.MaxBytesReader(w, r.Body, canvasRenderMaxBytes)
+	if err := r.ParseForm(); err != nil {
+		http.Error(w, "bad request", http.StatusBadRequest)
+		return
+	}
+	var out template.HTML
+	switch r.FormValue("type") {
+	case canvasNodeFile:
+		out = h.renderFileNode(r.FormValue("file"), r.FormValue("subpath"))
+	case canvasNodeText:
+		out = renderMarkdown([]byte(r.FormValue("text")))
+	default:
+		http.Error(w, "bad node type", http.StatusBadRequest)
+		return
+	}
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	_, _ = io.WriteString(w, string(out))
+}

diary.go

@@ -335,7 +335,7 @@ type calendarData struct {
 	Years        []calYear
 }
 
-var diaryCalTmpl = template.Must(template.New("calendar.html").Funcs(assetFuncs).ParseFS(assets, "assets/diary/calendar.html"))
+var diaryCalTmpl = template.Must(template.ParseFS(assets, "assets/diary/calendar.html"))
 
 func computeCalendarWidget(diaryRootFS, diaryRootURL, fsPath string, depth int) template.HTML {
 	today := time.Now()
@@ -533,8 +533,6 @@ type diarySection struct {
 	EditURL string        // year-file section edit URL ("" = no edit button)
 	Body    template.HTML // rendered markdown body (excludes the heading line)
 	Photos  []diaryPhoto
-	Events  string // day's calendar events, comma-separated (level 3 only)
-	Weight  string // day's weight from the weight calendar (level 3 only)
 }
 
 type diaryContentData struct {
@@ -625,7 +623,6 @@ func renderDiaryYear(yearFS, yearURL string) template.HTML {
 
 	out := buildFileSections(sections, photos, yearURL)
 	out = appendVirtualEntries(out, sections, photos, year, yearURL)
-	attachCalendarLines(out, year)
 	return renderDiaryContent(out)
 }
 
@@ -749,28 +746,6 @@ func appendVirtualEntries(existing []diarySection, sections [][]byte, photos []d
 	return out
 }
 
-// attachCalendarLines fills the events and weight lines of every day section
-// (real or virtual) from the calendars' diary and weight roles.
-func attachCalendarLines(sections []diarySection, year int) {
-	lines := calendarDayLines(
-		time.Date(year, time.January, 1, 0, 0, 0, 0, time.Local),
-		time.Date(year+1, time.January, 1, 0, 0, 0, 0, time.Local))
-	if len(lines) == 0 {
-		return
-	}
-	for i := range sections {
-		s := &sections[i]
-		if s.Level != 3 {
-			continue
-		}
-		if _, _, _, ok := parseISODate(s.ID); !ok {
-			continue
-		}
-		l := lines[s.ID[:10]]
-		s.Events, s.Weight = l.Events, l.Weight
-	}
-}
-
 // isRealDateSection reports whether a rendered diarySection is one of the
 // date-headed slots (`## YYYY-MM` or `### YYYY-MM-DD`) the virtual-entry
 // interleave sorts against.

embed.go

@@ -92,7 +92,7 @@ func (r *embedRenderer) render(w util.BufWriter, source []byte, node ast.Node, e
 		w.WriteString(strconv.Itoa(embedThumbW))
 		w.WriteString(`" alt="`)
 		w.Write(util.EscapeHTML([]byte(name)))
-		w.WriteString(`" loading="lazy"></a>`)
+		w.WriteString(`"></a>`)
 		if captioned {
 			w.WriteString(`<figcaption>`)
 		}

fitness.go

@@ -2,12 +2,14 @@ package main
 
 import (
 	"bytes"
+	"encoding/json"
 	"fmt"
 	"html/template"
 	"log"
 	"math"
 	"net/http"
-	"net/url"
+	"os"
+	"path/filepath"
 	"sort"
 	"strconv"
 	"strings"
@@ -18,6 +20,10 @@ func init() {
 	pageTypeHandlers = append(pageTypeHandlers, &fitnessHandler{})
 }
 
+// waistlineExportFile is the exact filename the user copies into the folder.
+// The single file is always the latest export — no glob, no multi-file merge.
+const waistlineExportFile = "waistline_export.json"
+
 type fitnessHandler struct{}
 
 // redirect: the fitness dashboard has no virtual URLs; everything renders
@@ -28,15 +34,16 @@ func (f *fitnessHandler) redirect(root, fsPath, urlPath string, r *http.Request)
 
 // handle renders the dashboard for folders whose .page-settings declares
 // type = fitness. Markdown content and the folder listing stay visible so
-// the folder can still hold notes.
+// the user can verify an uploaded export arrived.
 func (f *fitnessHandler) handle(root, fsPath, urlPath string, r *http.Request) *specialPage {
 	s := readPageSettings(fsPath)
 	if s == nil || s.Type != "fitness" {
 		return nil
 	}
-	q := r.URL.Query()
+	weightSel := validFitnessRange(r.URL.Query().Get("weight"), "3m")
+	weeklySel := validFitnessRange(r.URL.Query().Get("weekly"), "1y")
 	return &specialPage{
-		Content:     renderFitnessDashboard(fsPath, chartViewFrom(q, "weight", "3m"), chartViewFrom(q, "weekly", "1y")),
+		Content:     renderFitnessDashboard(fsPath, weightSel, weeklySel),
 		SuppressTOC: true,
 	}
 }
@@ -65,20 +72,6 @@ func validFitnessRange(v, fallback string) string {
 	return fallback
 }
 
-// fitnessView is one chart's view state from the query string: ?<param>=<range>
-// and ?<param>-absolute=1 to start the y axis at 0.
-type fitnessView struct {
-	Range    string
-	Absolute bool
-}
-
-func chartViewFrom(q url.Values, param, fallback string) fitnessView {
-	return fitnessView{
-		Range:    validFitnessRange(q.Get(param), fallback),
-		Absolute: q.Get(param+"-absolute") == "1",
-	}
-}
-
 func rangeMonths(v string) int {
 	for _, r := range fitnessRanges {
 		if r.Value == v {
@@ -88,6 +81,95 @@ func rangeMonths(v string) int {
 	return 0
 }
 
+// === Waistline export parsing ===
+
+// wlNum is a number in a Waistline export: values appear as JSON numbers,
+// numeric strings, null, or are absent. Unparsable values read as not-ok
+// instead of failing the whole export parse.
+type wlNum struct {
+	val float64
+	ok  bool
+}
+
+func (n *wlNum) UnmarshalJSON(b []byte) error {
+	s := strings.Trim(string(b), `"`)
+	if s == "" || s == "null" {
+		return nil
+	}
+	v, err := strconv.ParseFloat(s, 64)
+	if err != nil {
+		return nil
+	}
+	n.val = v
+	n.ok = true
+	return nil
+}
+
+// Calorie tracking was removed pending a rethink of the (undocumented)
+// per-item formula; only the weight series is read from the export.
+type wlExport struct {
+	Diary    []wlDiaryEntry  `json:"diary"`
+	Settings json.RawMessage `json:"settings"`
+}
+
+type wlDiaryEntry struct {
+	DateTime string `json:"dateTime"`
+	Stats    struct {
+		Weight wlNum `json:"weight"`
+	} `json:"stats"`
+}
+
+// exportDate extracts the calendar day from a Waistline dateTime. The values
+// are UTC-midnight timestamps; taking the first 10 characters avoids time
+// zone conversions shifting the day.
+func exportDate(s string) (time.Time, bool) {
+	if len(s) < 10 {
+		return time.Time{}, false
+	}
+	t, err := time.Parse("2006-01-02", s[:10])
+	if err != nil {
+		return time.Time{}, false
+	}
+	return t, true
+}
+
+// goalValue extracts settings.goals.<key>.goal-list[0].goal[0] — the first
+// weekday slot of the shared goal. Best-effort: any missing or unparsable
+// level means "no goal line", never an error.
+func goalValue(settings json.RawMessage, key string) (float64, bool) {
+	var s struct {
+		Goals map[string]json.RawMessage `json:"goals"`
+	}
+	if json.Unmarshal(settings, &s) != nil {
+		return 0, false
+	}
+	var g struct {
+		GoalList []struct {
+			Goal []wlNum `json:"goal"`
+		} `json:"goal-list"`
+	}
+	if json.Unmarshal(s.Goals[key], &g) != nil {
+		return 0, false
+	}
+	if len(g.GoalList) == 0 || len(g.GoalList[0].Goal) == 0 {
+		return 0, false
+	}
+	n := g.GoalList[0].Goal[0]
+	return n.val, n.ok
+}
+
+func exportWeightUnit(settings json.RawMessage) string {
+	var s struct {
+		Units struct {
+			Weight string `json:"weight"`
+		} `json:"units"`
+	}
+	if json.Unmarshal(settings, &s) == nil && s.Units.Weight != "" {
+		return s.Units.Weight
+	}
+	return "kg"
+}
+
 // === Series extraction ===
 
 type weightPoint struct {
@@ -96,34 +178,26 @@ type weightPoint struct {
 	days  int // >0: weekly mean over this many measured days
 }
 
-// fitnessWeights reads the whole weight calendar up to today: one point per
+// extractWeights computes the weight series from the export: one point per
-// day, sorted by date. Dates are UTC midnights to match the chart's today.
+// diary entry with stats.weight. Duplicate dates (shouldn't happen) — last
-func fitnessWeights(today time.Time) []weightPoint {
+// one wins.
-	byDay := calendarWeights(readCalendarSettings(calendarsDir), time.Time{}, today.AddDate(0, 0, 1))
+func extractWeights(ex *wlExport) []weightPoint {
-	weights := make([]weightPoint, 0, len(byDay))
+	byDate := map[time.Time]float64{}
-	for key, w := range byDay {
+	for _, e := range ex.Diary {
-		d, err := time.Parse("2006-01-02", key)
+		day, ok := exportDate(e.DateTime)
-		v, err2 := strconv.ParseFloat(w, 64)
+		if !ok || !e.Stats.Weight.ok {
-		if err != nil || err2 != nil {
 			continue
 		}
+		byDate[day] = e.Stats.Weight.val
+	}
+	weights := make([]weightPoint, 0, len(byDate))
+	for d, v := range byDate {
 		weights = append(weights, weightPoint{date: d, value: v})
 	}
 	sort.Slice(weights, func(i, j int) bool { return weights[i].date.Before(weights[j].date) })
 	return weights
 }
 
-// weightGoal reads the optional weight-goal key from the fitness folder's
-// .page-settings.
-func weightGoal(fsPath string) (float64, bool) {
-	v, ok := readSettingsFile(fsPath)["weight-goal"]
-	if !ok {
-		return 0, false
-	}
-	g, err := strconv.ParseFloat(strings.ReplaceAll(strings.TrimSpace(v), ",", "."), 64)
-	return g, err == nil
-}
-
 func mondayOf(t time.Time) time.Time {
 	return t.AddDate(0, 0, -((int(t.Weekday()) + 6) % 7))
 }
@@ -206,9 +280,8 @@ type fitnessTickVM struct {
 	Pos, Label, Anchor string
 }
 
-// fitnessDotVM is one data point; Date and Value feed the hover tooltip.
 type fitnessDotVM struct {
-	X, Y, Date, Value string
+	X, Y, Title string
 }
 
 type fitnessGoalVM struct {
@@ -216,11 +289,10 @@ type fitnessGoalVM struct {
 }
 
 type fitnessChartVM struct {
-	Title    string
+	Title   string
-	Param    string
+	Param   string
-	Options  []fitnessOptVM
+	Options []fitnessOptVM
-	Absolute bool
+	Empty   bool
-	Empty    bool
 
 	ViewW, ViewH               string
 	PlotX, PlotY, PlotR, PlotB string
@@ -229,7 +301,6 @@ type fitnessChartVM struct {
 	Goal                       *fitnessGoalVM
 	Lines                      []string // polyline points attributes
 	Dots                       []fitnessDotVM
-	Dense                      bool // too many points to draw markers
 }
 
 type fitnessDashVM struct {
@@ -237,13 +308,13 @@ type fitnessDashVM struct {
 	Charts []fitnessChartVM
 }
 
-func newChartVM(title, param string, view fitnessView) fitnessChartVM {
+func newChartVM(title, param, sel string) fitnessChartVM {
 	opts := make([]fitnessOptVM, len(fitnessRanges))
 	for i, r := range fitnessRanges {
-		opts[i] = fitnessOptVM{r.Value, r.Label, r.Value == view.Range}
+		opts[i] = fitnessOptVM{r.Value, r.Label, r.Value == sel}
 	}
 	return fitnessChartVM{
-		Title: title, Param: param, Options: opts, Absolute: view.Absolute,
+		Title: title, Param: param, Options: opts,
 		ViewW: svgNum(chartW), ViewH: svgNum(chartH),
 		PlotX: svgNum(chartLeft), PlotY: svgNum(chartTop),
 		PlotR: svgNum(chartW - chartRight), PlotB: svgNum(chartH - chartBottom),
@@ -252,7 +323,7 @@ func newChartVM(title, param string, view fitnessView) fitnessChartVM {
 }
 
 // yTickVMs places gridlines at fixed multiples of step across the y domain
-// (5 kg guides on weight charts, 20 kg when the axis starts at 0).
+// (always 5 kg guides on weight charts, regardless of range).
 func yTickVMs(sc chartScale, step float64) []fitnessTickVM {
 	var out []fitnessTickVM
 	for v := math.Ceil(sc.y0/step) * step; v <= sc.y1+step/1e6; v += step {
@@ -275,12 +346,12 @@ func (vm *fitnessChartVM) setGoal(sc chartScale, goal float64, label string) {
 // buildWeightChart renders a weight line chart. It serves both the per-day
 // series and the weekly-mean series (points carrying days > 0); the line is
 // drawn continuous across days/weeks without a measurement.
-func buildWeightChart(all []weightPoint, goal float64, hasGoal bool, view fitnessView, param, title, unit string, today time.Time) fitnessChartVM {
+func buildWeightChart(all []weightPoint, goal float64, hasGoal bool, sel, param, title, unit string, today time.Time) fitnessChartVM {
-	vm := newChartVM(title, param, view)
+	vm := newChartVM(title, param, sel)
 
 	points := all
 	var x0, x1 time.Time
-	if m := rangeMonths(view.Range); m > 0 {
+	if m := rangeMonths(sel); m > 0 {
 		x0 = today.AddDate(0, -m, 0)
 		points = filterWeights(all, x0)
 		if len(points) == 0 {
@@ -320,31 +391,21 @@ func buildWeightChart(all []weightPoint, goal float64, hasGoal bool, view fitnes
 		pad = 1
 	}
 	sc := chartScale{x0, x1, lo - pad, hi + pad}
-	yStep := 5.0
-	if view.Absolute {
-		sc.y0 = 0
-		sc.y1 = hi + hi*0.05
-		yStep = 20
-	}
 
-	vm.YTicks = yTickVMs(sc, yStep)
+	vm.YTicks = yTickVMs(sc, 5)
-	vm.XTicks = timeXTicks(sc)
+	vm.XTicks = timeXTicks(sc, 4)
 
 	// One continuous polyline through every point in range — days without a
-	// measurement do not break the line. Every point also gets a marker that
+	// measurement do not break the line. Point markers carry the hover
-	// feeds the hover tooltip; on dense ranges the markers are hidden and the
+	// <title>; on dense ranges they are dropped and the bare line stays
-	// bare line stays legible. A single point in range renders as a dot.
+	// legible. A single point in range renders as a dot.
 	dot := func(p weightPoint) fitnessDotVM {
-		d := fitnessDotVM{
+		label := p.date.Format("2006-01-02") + ": " + svgNum(p.value) + " " + unit
-			X: svgNum(sc.x(p.date)), Y: svgNum(sc.y(p.value)),
-			Date:  p.date.Format("Mon 2006-01-02"),
-			Value: svgNum(p.value) + " " + unit,
-		}
 		if p.days > 0 {
-			d.Date = "Week of " + p.date.Format("2006-01-02")
+			label = fmt.Sprintf("Week of %s: %s %s (%d days)",
-			d.Value += fmt.Sprintf(" · %d days", p.days)
+				p.date.Format("2006-01-02"), svgNum(p.value), unit, p.days)
 		}
-		return d
+		return fitnessDotVM{X: svgNum(sc.x(p.date)), Y: svgNum(sc.y(p.value)), Title: label}
 	}
 	if len(points) >= 2 {
 		var b strings.Builder
@@ -358,10 +419,11 @@ func buildWeightChart(all []weightPoint, goal float64, hasGoal bool, view fitnes
 		}
 		vm.Lines = append(vm.Lines, b.String())
 	}
-	for _, p := range points {
+	if len(points) <= 100 {
-		vm.Dots = append(vm.Dots, dot(p))
+		for _, p := range points {
+			vm.Dots = append(vm.Dots, dot(p))
+		}
 	}
-	vm.Dense = len(points) > 100
 
 	if hasGoal {
 		vm.setGoal(sc, goal, "goal "+svgNum(goal))
@@ -379,101 +441,34 @@ func filterWeights(points []weightPoint, from time.Time) []weightPoint {
 	return out
 }
 
-// xTickStep is a calendar-aligned spacing for date labels.
+// timeXTicks places n+1 evenly spaced date labels across a continuous time
-type xTickStep struct {
+// axis; the last label is end-anchored so it stays inside the viewBox.
-	days, months int
+func timeXTicks(sc chartScale, n int) []fitnessTickVM {
-	label        func(t time.Time, first bool) string
+	span := sc.x1.Sub(sc.x0)
-}
+	var out []fitnessTickVM
-
+	prev := ""
-var xTickSteps = []xTickStep{
+	for i := 0; i <= n; i++ {
-	{days: 1, label: dayLabel},
+		t := sc.x0.Add(time.Duration(float64(span) * float64(i) / float64(n)))
-	{days: 7, label: dayLabel},
+		label := t.Format("2006-01-02")
-	{days: 14, label: dayLabel},
+		if label == prev {
-	{months: 1, label: monthLabel},
+			continue
-	{months: 3, label: monthLabel},
-	{months: 6, label: monthLabel},
-	{months: 12, label: yearLabel},
-	{months: 24, label: yearLabel},
-	{months: 60, label: yearLabel},
-}
-
-func dayLabel(t time.Time, _ bool) string { return t.Format("2 Jan") }
-
-// monthLabel names the year only where it changes, so a year-long axis
-// reads "Oct 2025, Jan 2026, Apr, Jul".
-func monthLabel(t time.Time, first bool) string {
-	if first || t.Month() == time.January {
-		return t.Format("Jan 2006")
-	}
-	return t.Format("Jan")
-}
-
-func yearLabel(t time.Time, _ bool) string { return t.Format("2006") }
-
-// maxXTicks bounds the label count so labels never collide on the axis.
-const maxXTicks = 5
-
-// timeXTicks labels the time axis at calendar boundaries — days, Mondays,
-// month starts or new years, whichever is the finest step that stays within
-// maxXTicks. Labels near the plot edges are anchored inward so they stay
-// inside the viewBox.
-func timeXTicks(sc chartScale) []fitnessTickVM {
-	var ticks []time.Time
-	var step xTickStep
-	for _, step = range xTickSteps {
-		ticks = alignedTicks(sc.x0, sc.x1, step)
-		if len(ticks) <= maxXTicks {
-			break
 		}
-	}
+		prev = label
-	out := make([]fitnessTickVM, 0, len(ticks))
-	for i, t := range ticks {
-		x := sc.x(t)
 		anchor := "middle"
-		switch {
+		if i == n {
-		case x-chartLeft < 24:
-			anchor = "start"
-		case chartW-chartRight-x < 24:
 			anchor = "end"
 		}
-		out = append(out, fitnessTickVM{Pos: svgNum(x), Label: step.label(t, i == 0), Anchor: anchor})
+		out = append(out, fitnessTickVM{Pos: svgNum(sc.x(t)), Label: label, Anchor: anchor})
-	}
-	return out
-}
-
-// alignedTicks lists every boundary of step within [from, to]. Week steps
-// start on Mondays; month and year steps on multiples of the step (Jan/Apr/
-// Jul/Oct for quarters, even years for two-year steps).
-func alignedTicks(from, to time.Time, step xTickStep) []time.Time {
-	var t time.Time
-	if step.days > 0 {
-		t = time.Date(from.Year(), from.Month(), from.Day(), 0, 0, 0, 0, time.UTC)
-		if step.days > 1 {
-			t = mondayOf(t)
-		}
-	} else {
-		months := from.Year()*12 + int(from.Month()) - 1
-		months -= months % step.months
-		t = time.Date(months/12, time.Month(months%12+1), 1, 0, 0, 0, 0, time.UTC)
-	}
-	var out []time.Time
-	for ; !t.After(to); t = t.AddDate(0, step.months, step.days) {
-		if !t.Before(from) {
-			out = append(out, t)
-		}
-		if len(out) > maxXTicks {
-			break
-		}
 	}
 	return out
 }
 
 // === Rendering ===
 
-var fitnessTmpl = template.Must(template.New("main.html").Funcs(assetFuncs).ParseFS(assets, "assets/fitness/main.html"))
+var fitnessTmpl = template.Must(template.ParseFS(assets, "assets/fitness/main.html"))
 
-func renderFitnessDashboard(fsPath string, weightView, weeklyView fitnessView) template.HTML {
+func renderFitnessDashboard(fsPath, weightSel, weeklySel string) template.HTML {
-	data := buildFitnessDash(fsPath, weightView, weeklyView, time.Now())
+	data := buildFitnessDash(fsPath, weightSel, weeklySel, time.Now())
 	var buf bytes.Buffer
 	if err := fitnessTmpl.Execute(&buf, data); err != nil {
 		log.Printf("fitness template: %v", err)
@@ -482,23 +477,28 @@ func renderFitnessDashboard(fsPath string, weightView, weeklyView fitnessView) t
 	return template.HTML(buf.String())
 }
 
-// buildFitnessDash reads the weight calendar per request (the calendar store
+// buildFitnessDash reads and parses the export per request — no caching, no
-// caches parsed files). A missing calendar setup becomes an inline notice;
+// indexes. A read or parse failure (including a truncated mid-upload file)
-// the page itself always renders.
+// becomes an inline notice; the page itself always renders.
-func buildFitnessDash(fsPath string, weightView, weeklyView fitnessView, now time.Time) fitnessDashVM {
+func buildFitnessDash(fsPath, weightSel, weeklySel string, now time.Time) fitnessDashVM {
-	if calendarsDir == "" || len(readCalendarSettings(calendarsDir).Weight) == 0 {
+	raw, err := os.ReadFile(filepath.Join(fsPath, waistlineExportFile))
-		return fitnessDashVM{Notice: "No weight calendar configured — set weight = <calendar> in the calendars folder's .page-settings."}
+	if err != nil {
+		return fitnessDashVM{Notice: "No Waistline export found — upload " + waistlineExportFile + " to this folder."}
+	}
+	var ex wlExport
+	if err := json.Unmarshal(raw, &ex); err != nil {
+		return fitnessDashVM{Notice: "Could not read " + waistlineExportFile + ": " + err.Error()}
 	}
 
 	today := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, time.UTC)
-	weights := fitnessWeights(today)
+	weights := extractWeights(&ex)
-	wGoal, hasWGoal := weightGoal(fsPath)
+	wGoal, hasWGoal := goalValue(ex.Settings, "weight")
-	const unit = "kg"
+	unit := exportWeightUnit(ex.Settings)
 
 	return fitnessDashVM{Charts: []fitnessChartVM{
-		buildWeightChart(weights, wGoal, hasWGoal, weightView,
+		buildWeightChart(weights, wGoal, hasWGoal, weightSel,
 			"weight", "Weight ("+unit+")", unit, today),
-		buildWeightChart(weeklyMeanWeights(weights), wGoal, hasWGoal, weeklyView,
+		buildWeightChart(weeklyMeanWeights(weights), wGoal, hasWGoal, weeklySel,
 			"weekly", "Weekly average weight ("+unit+")", unit, today),
 	}}
 }

fitness_test.go

@@ -1,76 +0,0 @@
-package main
-
-import (
-	"os"
-	"strings"
-	"path/filepath"
-	"testing"
-	"time"
-)
-
-func TestFitnessWeights(t *testing.T) {
-	withBerlin(t)
-	dir := t.TempDir()
-	prev := calendarsDir
-	calendarsDir = dir
-	t.Cleanup(func() { calendarsDir = prev })
-
-	if err := os.WriteFile(filepath.Join(dir, ".page-settings"),
-		[]byte("type = calendars\nweight = Gewicht\n"), 0644); err != nil {
-		t.Fatal(err)
-	}
-	writeCal(t, dir, "Gewicht",
-		`UID:1
-		SUMMARY:96 kg
-		DTSTART;VALUE=DATE:20261001`,
-		`UID:2
-		SUMMARY:95,6kg
-		DTSTART;VALUE=DATE:20261003`,
-		`UID:3
-		SUMMARY:not a weight
-		DTSTART;VALUE=DATE:20261004`,
-		`UID:4
-		SUMMARY:90 kg
-		DTSTART;VALUE=DATE:20261010`,
-	)
-
-	today := time.Date(2026, 10, 5, 0, 0, 0, 0, time.UTC)
-	got := fitnessWeights(today)
-	want := []weightPoint{
-		{date: time.Date(2026, 10, 1, 0, 0, 0, 0, time.UTC), value: 96},
-		{date: time.Date(2026, 10, 3, 0, 0, 0, 0, time.UTC), value: 95.6},
-	}
-	if len(got) != len(want) {
-		t.Fatalf("got %+v, want %+v", got, want)
-	}
-	for i := range want {
-		if !got[i].date.Equal(want[i].date) || got[i].value != want[i].value {
-			t.Fatalf("point %d: got %+v, want %+v", i, got[i], want[i])
-		}
-	}
-}
-
-func TestTimeXTicks(t *testing.T) {
-	d := func(y int, m time.Month, day int) time.Time { return time.Date(y, m, day, 0, 0, 0, 0, time.UTC) }
-	for _, c := range []struct {
-		from, to time.Time
-		want     string
-	}{
-		{d(2022, 11, 28), d(2026, 9, 21), "2023 2024 2025 2026"},
-		{d(2025, 9, 27), d(2026, 9, 27), "Oct 2025|Jan 2026|Apr|Jul"},
-		{d(2026, 6, 27), d(2026, 9, 27), "Jul 2026|Aug|Sep"},
-		{d(2026, 8, 27), d(2026, 9, 27), "31 Aug|7 Sep|14 Sep|21 Sep"},
-	} {
-		var got []string
-		for _, tk := range timeXTicks(chartScale{x0: c.from, x1: c.to}) {
-			got = append(got, tk.Label)
-		}
-		sep := " "
-		if strings.Contains(c.want, "|") {
-			sep = "|"
-		}
-		if g := strings.Join(got, sep); g != c.want {
-			t.Errorf("%s..%s: got %q, want %q", c.from.Format("2006-01-02"), c.to.Format("2006-01-02"), g, c.want)
-		}
-	}
-}

go.mod

@@ -2,8 +2,4 @@ module datascape
 
 go 1.26.1
 
-require (
+require github.com/yuin/goldmark v1.8.2
-	github.com/emersion/go-ical v0.0.0-20250609112844-439c63cef608
-	github.com/teambition/rrule-go v1.8.2
-	github.com/yuin/goldmark v1.8.2
-)

go.sum

@@ -1,6 +1,2 @@
-github.com/emersion/go-ical v0.0.0-20250609112844-439c63cef608 h1:5XWaET4YAcppq3l1/Yh2ay5VmQjUdq6qhJuucdGbmOY=
-github.com/emersion/go-ical v0.0.0-20250609112844-439c63cef608/go.mod h1:BEksegNspIkjCQfmzWgsgbu6KdeJ/4LwUZs7DMBzjzw=
-github.com/teambition/rrule-go v1.8.2 h1:lIjpjvWTj9fFUZCmuoVDrKVOtdiyzbzc93qTmRVe/J8=
-github.com/teambition/rrule-go v1.8.2/go.mod h1:Ieq5AbrKGciP1V//Wq8ktsTXwSwJHDD5mD/wLBGl3p4=
 github.com/yuin/goldmark v1.8.2 h1:kEGpgqJXdgbkhcOgBxkC0X0PmoPG1ZyoZ117rDVp4zE=
 github.com/yuin/goldmark v1.8.2/go.mod h1:ip/1k0VRfGynBgxOz0yCqHrbZXhcjxyuS66Brc7iBKg=

main.go

@@ -2,9 +2,12 @@ package main
 
 import (
 	"context"
+	"crypto/sha256"
 	"embed"
+	"encoding/hex"
 	"flag"
 	"html/template"
+	"io/fs"
 	"log"
 	"net/http"
 	"net/url"
@@ -14,26 +17,38 @@ import (
 	"strconv"
 	"strings"
 	"time"
-	_ "time/tzdata" // calendar TZIDs must resolve even without system zoneinfo
 )
 
 //go:embed assets
 var assets embed.FS
 
-// tmplFuncs is shared by every layout-based template: asset links versioned
+// editorBundleVersion is a short content hash of the vendored CodeMirror bundle,
-// static files (see static.go); the layout header renders the maintenance
+// appended as ?v=… to its <script> src. The bundle is served immutable under a
-// widget.
+// stable filename, so without this query a rebuilt bundle would never reach a
+// client that already cached the old one (this is the editor cache-bust knob).
+var editorBundleVersion = hashAsset("assets/editor/vendor/codemirror.bundle.js")
+
+func hashAsset(name string) string {
+	b, err := assets.ReadFile(name)
+	if err != nil {
+		return ""
+	}
+	sum := sha256.Sum256(b)
+	return hex.EncodeToString(sum[:])[:12]
+}
+
+// tmplFuncs is shared by every layout-based template: the edit template appends
+// editorBundleVersion to its CodeMirror <script> src to cache-bust the bundle.
 var tmplFuncs = template.FuncMap{
-	"asset":             assetURL,
+	"editorBundleVersion": func() string { return editorBundleVersion },
-	"fileIcon":          fileIcon,
+	"fileIcon":            fileIcon,
-	"icon":              readIcon,
-	"maintenanceWidget": maintenanceWidget,
 }
 
 var (
 	pageTmpl   = template.Must(template.New("page").Funcs(tmplFuncs).ParseFS(assets, "assets/layout.html", "assets/page/main.html"))
 	editTmpl   = template.Must(template.New("edit").Funcs(tmplFuncs).ParseFS(assets, "assets/layout.html", "assets/editor/main.html"))
 	searchTmpl = template.Must(template.New("search").Funcs(tmplFuncs).ParseFS(assets, "assets/layout.html", "assets/search/main.html"))
+	canvasTmpl = template.Must(template.New("canvas").Funcs(tmplFuncs).ParseFS(assets, "assets/layout.html", "assets/canvas/main.html"))
 )
 
 // specialPage is the result returned by a pageTypeHandler.
@@ -74,18 +89,8 @@ func main() {
 	user := flag.String("user", "", "basic auth username (empty = no auth)")
 	pass := flag.String("pass", "", "basic auth password")
 	reindexInterval := flag.Duration("reindex-interval", 30*time.Minute, "periodic search index rebuild interval (0 disables)")
-	calendars := flag.String("calendars", "Calendars", "calendars folder, relative to -dir (empty disables)")
-	tz := flag.String("tz", "", "time zone for calendars and the diary, e.g. Europe/Berlin (default: system)")
 	flag.Parse()
 
-	if *tz != "" {
-		loc, err := time.LoadLocation(*tz)
-		if err != nil {
-			log.Fatalf("-tz: %v", err)
-		}
-		time.Local = loc
-	}
-
 	root, err := filepath.Abs(*wikiDir)
 	if err != nil {
 		log.Fatal(err)
@@ -104,25 +109,24 @@ func main() {
 
 	initMarkdown()
 
-	if *calendars != "" {
-		calendarsDir = filepath.Join(root, filepath.FromSlash(*calendars))
-		rel, err := filepath.Rel(root, calendarsDir)
-		if err != nil || rel == "." || strings.HasPrefix(rel, "..") {
-			log.Fatalf("-calendars must be a folder inside -dir")
-		}
-		calendarsURL = "/" + filepath.ToSlash(rel) + "/"
-	}
-
 	authKey, err := loadOrCreateAuthKey(root)
 	if err != nil {
 		log.Fatal(err)
 	}
 	h := &handler{root: root, user: *user, pass: *pass, authKey: authKey}
 
-	http.Handle("/_/", serveStatic())
+	staticFS, _ := fs.Sub(assets, "assets")
+	static := http.StripPrefix("/_/", http.FileServer(http.FS(staticFS)))
+	http.Handle("/_/", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if strings.HasPrefix(r.URL.Path, "/_/fonts/") || strings.HasPrefix(r.URL.Path, "/_/editor/vendor/") {
+			w.Header().Set("Cache-Control", "public, max-age=31536000, immutable")
+		}
+		static.ServeHTTP(w, r)
+	}))
 	http.HandleFunc("/_logout", h.handleLogout)
 	http.HandleFunc("/_reindex", h.handleReindex)
 	http.HandleFunc("/_search", h.handleSearchSuggest)
+	http.HandleFunc("/_canvas/render", h.handleCanvasRender)
 	http.HandleFunc("/quickadd", h.handleQuickAdd)
 	http.Handle("/", h)
 
@@ -156,10 +160,6 @@ func main() {
 		}(*reindexInterval)
 	}
 
-	if calendarsDir != "" {
-		startCalendarSync()
-	}
-
 	log.Printf("datascape listening on %s, wiki at %s", *addr, root)
 	log.Fatal(http.ListenAndServe(*addr, nil))
 }
@@ -175,21 +175,14 @@ type reqStartKeyT struct{}
 
 var reqStartKey = reqStartKeyT{}
 
-// requestStart returns when the request entered ServeHTTP, or now if unknown.
+// elapsedMS returns the milliseconds since the request entered ServeHTTP.
-func requestStart(r *http.Request) time.Time {
+func elapsedMS(r *http.Request) int64 {
 	if start, ok := r.Context().Value(reqStartKey).(time.Time); ok {
-		return start
+		return time.Since(start).Milliseconds()
 	}
-	return time.Now()
+	return 0
 }
 
-// renderTimer is embedded in template data. The footer calls RenderMS while
-// the template executes, so the time includes the page's own rendering (and
-// the header's maintenance widget), not just the work before it.
-type renderTimer struct{ start time.Time }
-
-func (t renderTimer) RenderMS() int64 { return time.Since(t.start).Milliseconds() }
-
 func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	r = r.WithContext(context.WithValue(r.Context(), reqStartKey, time.Now()))
 
@@ -197,14 +190,6 @@ func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// Dotfiles are never served: .page-settings can hold the CalDAV
-	// password and .auth-key signs sessions. Nothing links to them (listing,
-	// tree and search hide them already).
-	if hasDotSegment(r.URL.Path) {
-		http.NotFound(w, r)
-		return
-	}
-
 	if strings.HasPrefix(r.URL.Path, thumbURLPrefix+"/") {
 		h.handleThumb(w, r)
 		return
@@ -230,6 +215,16 @@ func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// A canvas is addressed as a view of its folder (?canvas=Name), so a direct
+	// hit on the file collapses onto that canonical form — the same shape as
+	// diary.go's virtual-URL redirects. ?raw keeps the bytes reachable.
+	if r.Method == http.MethodGet && strings.HasSuffix(urlPath, canvasExt) && !r.URL.Query().Has("raw") {
+		if target, ok := canvasViewURL(urlPath); ok {
+			http.Redirect(w, r, target, http.StatusFound)
+			return
+		}
+	}
+
 	info, err := os.Stat(fsPath)
 	if err != nil {
 		if os.IsNotExist(err) {
@@ -272,17 +267,6 @@ func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
-// hasDotSegment reports whether any segment of the cleaned URL path starts
-// with a dot.
-func hasDotSegment(p string) bool {
-	for _, seg := range strings.Split(path.Clean("/"+p), "/") {
-		if strings.HasPrefix(seg, ".") {
-			return true
-		}
-	}
-	return false
-}
-
 // slashedURL returns u's path with a trailing slash appended and the query
 // string intact — the canonical page form that relative destinations resolve
 // against.
@@ -302,6 +286,19 @@ func (h *handler) serveDir(w http.ResponseWriter, r *http.Request, urlPath, fsPa
 		return
 	}
 
+	// An explicit ?canvas= selects this page's canvas view. Checked ahead of
+	// the pageTypeHandler redirect loop so an explicit view request always wins
+	// over a folder-type redirect (e.g. a canvas kept in a diary year folder).
+	//
+	// This is deliberately not a pageTypeHandler: that interface injects content
+	// into the standard page body, while a canvas replaces the whole body with a
+	// full-bleed surface and its own controls — a view mode like ?edit, which is
+	// likewise a template branch here rather than a handler.
+	if name := r.URL.Query().Get("canvas"); name != "" {
+		h.serveCanvas(w, r, urlPath, fsPath, name)
+		return
+	}
+
 	for _, ph := range pageTypeHandlers {
 		if target, ok := ph.redirect(h.root, fsPath, urlPath, r); ok {
 			http.Redirect(w, r, target, http.StatusFound)
@@ -344,6 +341,14 @@ func (h *handler) serveDir(w http.ResponseWriter, r *http.Request, urlPath, fsPa
 		rendered = renderMarkdown(rawMD)
 	}
 
+	// Canvases in this folder surface as a view switcher above the content, so
+	// a page and its diagrams read as one thing. Suppressed in the editor, which
+	// is about the markdown only.
+	var canvases []canvasRef
+	if !editMode {
+		canvases = listCanvases(fsPath, urlPath, "")
+	}
+
 	view, sortKey, order := readPageSettings(fsPath).viewSettings()
 	var entries []entry
 	if !editMode && (special == nil || !special.SuppressListing) {
@@ -407,6 +412,7 @@ func (h *handler) serveDir(w http.ResponseWriter, r *http.Request, urlPath, fsPa
 		SpecialContent: specialContent,
 		SidebarWidget:  sidebarWidget,
 		SuppressTOC:    suppressTOC,
+		Canvases:       canvases,
 	}
 
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
@@ -414,7 +420,7 @@ func (h *handler) serveDir(w http.ResponseWriter, r *http.Request, urlPath, fsPa
 	if editMode {
 		t = editTmpl
 	}
-	data.renderTimer = renderTimer{requestStart(r)}
+	data.RenderMS = elapsedMS(r)
 	if err := t.ExecuteTemplate(w, "layout", data); err != nil {
 		log.Printf("template error: %v", err)
 	}
@@ -422,6 +428,12 @@ func (h *handler) serveDir(w http.ResponseWriter, r *http.Request, urlPath, fsPa
 
 func (h *handler) handlePost(w http.ResponseWriter, r *http.Request, urlPath, fsPath string) {
 	query := r.URL.Query()
+	// Checked first so ?canvas=X&delete removes that canvas rather than falling
+	// through to the page-level delete below.
+	if name := query.Get("canvas"); name != "" {
+		h.handleCanvasPost(w, r, urlPath, fsPath, name)
+		return
+	}
 	if query.Has("delete") {
 		h.handleDelete(w, r, urlPath, fsPath)
 		return
@@ -442,10 +454,6 @@ func (h *handler) handlePost(w http.ResponseWriter, r *http.Request, urlPath, fs
 		h.handleSettings(w, r, urlPath, fsPath)
 		return
 	}
-	if query.Has("calsync") {
-		h.handleCalendarSync(w, r, urlPath, fsPath)
-		return
-	}
 
 	if err := r.ParseForm(); err != nil {
 		http.Error(w, "bad request", http.StatusBadRequest)
@@ -557,28 +565,12 @@ func (h *handler) handlePost(w http.ResponseWriter, r *http.Request, urlPath, fs
 // Returns nil if the file does not exist.
 // Format: one "key = value" pair per line; lines starting with # are comments.
 func readPageSettings(dir string) *pageSettings {
-	kv := readSettingsFile(dir)
-	if kv == nil {
-		return nil
-	}
-	// Unknown or missing values fall back to the defaults.
-	return &pageSettings{
-		Type:  kv["type"],
-		View:  validateView(kv["view"]),
-		Sort:  validateSort(kv["sort"]),
-		Order: validateOrder(kv["order"]),
-	}
-}
-
-// readSettingsFile returns every key of dir's .page-settings (last one wins),
-// or nil if the file does not exist. Other features (e.g. the calendars
-// folder) keep their own keys in the same file.
-func readSettingsFile(dir string) map[string]string {
 	data, err := os.ReadFile(filepath.Join(dir, ".page-settings"))
 	if err != nil {
 		return nil
 	}
-	kv := map[string]string{}
+	// Defaults; overridden only by valid values present in the file.
+	s := &pageSettings{View: viewList, Sort: sortName, Order: orderAsc}
 	for _, line := range strings.Split(string(data), "\n") {
 		line = strings.TrimSpace(line)
 		if line == "" || strings.HasPrefix(line, "#") {
@@ -588,7 +580,17 @@ func readSettingsFile(dir string) map[string]string {
 		if len(parts) != 2 {
 			continue
 		}
-		kv[strings.TrimSpace(parts[0])] = strings.TrimSpace(parts[1])
+		value := strings.TrimSpace(parts[1])
+		switch strings.TrimSpace(parts[0]) {
+		case "type":
+			s.Type = value
+		case "view":
+			s.View = validateView(value)
+		case "sort":
+			s.Sort = validateSort(value)
+		case "order":
+			s.Order = validateOrder(value)
+		}
 	}
-	return kv
+	return s
 }

maintenance.go

@@ -1,144 +0,0 @@
-package main
-
-import (
-	"bytes"
-	"html/template"
-	"log"
-	"sort"
-	"time"
-)
-
-// calendarsURL is the page URL of calendarsDir ("/Calendars/").
-var calendarsURL string
-
-// maintenanceHorizon is how many days after today the header widget lists.
-const maintenanceHorizon = 7
-
-type maintItem struct {
-	When    string // "03:00" today; "Sa 27.09." or "Sa 27.09. 03:00" later
-	Summary string
-}
-
-type maintWidgetData struct {
-	Count    int // occurrences today (the badge)
-	Today    []maintItem
-	Upcoming []maintItem
-	PageURL  string
-}
-
-var maintWidgetTmpl = template.Must(template.New("widget.html").
-	Funcs(template.FuncMap{"icon": readIcon}).
-	ParseFS(assets, "assets/calendar/widget.html"))
-
-// maintenanceWidget renders the header chip and its dropdown. It is a
-// template func so layout.html can call it without every page's data struct
-// carrying it. Empty when no maintenance calendar is configured.
-func maintenanceWidget() template.HTML {
-	if calendarsDir == "" {
-		return ""
-	}
-	names := readCalendarSettings(calendarsDir).Maintenance
-	if len(names) == 0 {
-		return ""
-	}
-	now := time.Now()
-	today := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, time.Local)
-	tomorrow := today.AddDate(0, 0, 1)
-
-	data := maintWidgetData{PageURL: calendarsURL}
-	for _, ev := range calendarOccurrences(calendarsDir, names, today, today.AddDate(0, 0, maintenanceHorizon+1)) {
-		// Anything that started before tomorrow is due today, including
-		// multi-day events still running.
-		if ev.Start.Before(tomorrow) {
-			item := maintItem{Summary: ev.Summary}
-			if !ev.AllDay && !ev.Start.Before(today) {
-				item.When = ev.Start.Format("15:04")
-			}
-			data.Today = append(data.Today, item)
-			continue
-		}
-		when := calDayLabel(ev.Start)
-		if !ev.AllDay {
-			when += " " + ev.Start.Format("15:04")
-		}
-		data.Upcoming = append(data.Upcoming, maintItem{When: when, Summary: ev.Summary})
-	}
-	data.Count = len(data.Today)
-
-	var buf bytes.Buffer
-	if err := maintWidgetTmpl.Execute(&buf, data); err != nil {
-		log.Printf("maintenance widget template: %v", err)
-		return ""
-	}
-	return template.HTML(buf.String())
-}
-
-// maintSeriesRow is one task in the calendars page's maintenance table.
-type maintSeriesRow struct {
-	Summary string
-	Rule    string
-	Last    string // most recent occurrence before today
-	Next    string // first occurrence today or later
-	next    time.Time
-}
-
-// maintenanceWindow bounds the table's occurrence search, in days each way
-// from today. A year covers yearly tasks.
-const maintenanceWindow = 366
-
-// maintenanceSeries lists every task of the named calendars in dir: one row
-// per recurring series with its last and next date, plus upcoming single
-// events. Sorted by next date; series without a next date come last.
-func maintenanceSeries(dir string, names []string, now time.Time) []maintSeriesRow {
-	today := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, time.Local)
-	evs := calendarOccurrences(dir, names, today.AddDate(0, 0, -maintenanceWindow), today.AddDate(0, 0, maintenanceWindow))
-
-	type key struct{ calendar, uid string }
-	rows := map[key]*maintSeriesRow{}
-	var order []*maintSeriesRow
-	for _, ev := range evs {
-		if ev.Series == nil {
-			if ev.Start.Before(today) {
-				continue
-			}
-			order = append(order, &maintSeriesRow{
-				Summary: ev.Summary,
-				Rule:    "once",
-				Next:    calDayLabel(ev.Start),
-				next:    ev.Start,
-			})
-			continue
-		}
-		k := key{ev.Calendar, ev.Series.UID}
-		row := rows[k]
-		if row == nil {
-			row = &maintSeriesRow{Summary: ev.Series.Summary, Rule: ev.Series.Rule}
-			rows[k] = row
-			order = append(order, row)
-		}
-		// Occurrences arrive sorted by start: keep overwriting Last, take
-		// the first one from today on as Next.
-		if ev.Start.Before(today) {
-			row.Last = calDayLabel(ev.Start)
-		} else if row.next.IsZero() {
-			row.next = ev.Start
-			row.Next = calDayLabel(ev.Start)
-		}
-	}
-
-	out := make([]maintSeriesRow, 0, len(order))
-	for _, r := range order {
-		out = append(out, *r)
-	}
-	sort.SliceStable(out, func(i, j int) bool {
-		a, b := out[i].next, out[j].next
-		if a.IsZero() != b.IsZero() {
-			return b.IsZero()
-		}
-		if !a.Equal(b) {
-			return a.Before(b)
-		}
-		return out[i].Summary < out[j].Summary
-	})
-	return out
-}

quickadd.go

@@ -11,7 +11,7 @@ import (
 	"time"
 )
 
-var quickAddTmpl = template.Must(template.New("quickadd.html").Funcs(assetFuncs).ParseFS(assets, "assets/quickadd.html"))
+var quickAddTmpl = template.Must(template.ParseFS(assets, "assets/quickadd.html"))
 
 type quickAddData struct {
 	To, URL, Title string

render.go

@@ -63,7 +63,40 @@ type pageData struct {
 	SpecialContent template.HTML
 	SidebarWidget  template.HTML
 	SuppressTOC    bool
-	renderTimer
+	RenderMS       int64
+
+	// Canvases lists every .canvas file in this folder as a view-switcher tab.
+	// ActiveCanvas names the one currently being viewed ("" on a normal page),
+	// and is what makes this page render as a canvas rather than as markdown.
+	Canvases     []canvasRef
+	ActiveCanvas string
+	// CanvasJSON is the whole canvas document plus its server-rendered node
+	// HTML, inlined into the page so opening a canvas costs one request.
+	CanvasJSON template.JS
+	// CanvasError carries a parse/validation failure to the template, which
+	// shows it in place of the canvas instead of failing the request.
+	CanvasError string
+}
+
+// layoutData is the contract every view built on assets/layout.html satisfies.
+// The layout is shared by pageData and searchPageData, and a method only one of
+// them has fails at render time with a half-written response rather than at
+// build time — so each is asserted against the interface here.
+type layoutData interface {
+	ShowPageChrome() bool
+}
+
+var (
+	_ layoutData = pageData{}
+	_ layoutData = searchPageData{}
+)
+
+// ShowPageChrome reports whether the standard page furniture — search box,
+// folder-tree rail, right sidebar, and the collapsed ACTIONS dropdown — should
+// render. The editor and the canvas view both take the full width and supply
+// their own controls, so both opt out.
+func (d pageData) ShowPageChrome() bool {
+	return !d.EditMode && d.ActiveCanvas == ""
 }
 
 // Allowed values for the listing view settings. Unknown values in the file or
@@ -130,6 +163,7 @@ var (
 	iconAudio   = readIcon("audio")
 	iconArchive = readIcon("archive")
 	iconGeneric = readIcon("generic")
+	iconCanvas  = readIcon("canvas")
 )
 
 // renderMarkdown converts raw markdown to trusted HTML.
@@ -211,6 +245,9 @@ func listEntries(fsPath, urlPath, sortKey, order string) []entry {
 			if name == "index.md" {
 				continue // rendered above, don't list it
 			}
+			if isCanvasFile(name) {
+				continue // surfaced as a view-switcher tab above the content
+			}
 			f := entry{
 				Icon:    fileIcon(name),
 				Name:    name,
@@ -300,6 +337,8 @@ func readIcon(name string) template.HTML {
 func fileIcon(name string) template.HTML {
 	ext := strings.ToLower(path.Ext(name))
 	switch ext {
+	case ".canvas":
+		return iconCanvas
 	case ".md", ".pdf":
 		return iconDoc
 	case ".png", ".jpg", ".jpeg", ".gif", ".webp", ".svg":

search.go

@@ -12,7 +12,6 @@ import (
 	"sync"
 	"time"
 	"unicode"
-	"unicode/utf8"
 )
 
 // searchSectionCap bounds how many rows each results section renders. The
@@ -47,9 +46,14 @@ type searchPageData struct {
 	PageTotal    int
 	FileTotal    int
 	IndexBuiltAt time.Time
-	renderTimer
+	RenderMS     int64
 }
 
+// ShowPageChrome satisfies the shared layout's contract (see layoutData). The
+// results page is always ordinary chrome — it is never the editor and never a
+// canvas — but EditMode is honoured so the two views cannot drift apart.
+func (d searchPageData) ShowPageChrome() bool { return !d.EditMode }
+
 // indexEntry is the shared scoreable core of both folder and file index
 // entries: a forward-slash relative path plus its pre-tokenized basename so
 // the per-query scoring loop avoids redoing the lowercasing and tokenization
@@ -133,7 +137,7 @@ func (h *handler) handleSearch(w http.ResponseWriter, r *http.Request) {
 		IndexBuiltAt: builtAt,
 	}
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
-	data.renderTimer = renderTimer{requestStart(r)}
+	data.RenderMS = elapsedMS(r)
 	if err := searchTmpl.ExecuteTemplate(w, "layout", data); err != nil {
 		log.Printf("search template error: %v", err)
 	}
@@ -279,7 +283,7 @@ func scoreName(nameLower string, nameTokens []string, qLower string, qTokens []s
 				if best < 20 {
 					best = 20
 				}
-			case fuzzy && withinTwoEdits(w, qt):
+			case fuzzy && levenshtein(w, qt) <= 2:
 				if best < 5 {
 					best = 5
 				}
@@ -576,17 +580,6 @@ func tokenize(s string) []string {
 	return tokens
 }
 
-// withinTwoEdits reports whether a and b are at most 2 edits apart. Lengths
-// differing by more than 2 rule that out without running levenshtein, which
-// skips nearly every word pair in the per-query scoring loop.
-func withinTwoEdits(a, b string) bool {
-	d := utf8.RuneCountInString(a) - utf8.RuneCountInString(b)
-	if d < -2 || d > 2 {
-		return false
-	}
-	return levenshtein(a, b) <= 2
-}
-
 // levenshtein returns the edit distance between a and b. Operates on runes so
 // multi-byte characters count as one edit.
 func levenshtein(a, b string) int {

sections.go

@@ -91,7 +91,7 @@ func secionSpanEnd(sections [][]byte, start int) int {
 	if level == 0 {
 		return start + 1
 	}
-	for i := start + 1; i <= len(sections); i++ {
+	for i := start + 1; i < len(sections); i++ {
 		if l, _ := sectionHeading(sections[i]); l > 0 && l <= level {
 			return i
 		}

static.go

@@ -1,135 +0,0 @@
-package main
-
-import (
-	"bytes"
-	"compress/gzip"
-	"crypto/sha256"
-	"encoding/hex"
-	"fmt"
-	"html/template"
-	"io/fs"
-	"net/http"
-	"strings"
-	"time"
-)
-
-// assetVersions maps each embedded asset (path relative to assets/, e.g.
-// "page/toc.js") to a short hash of its content. Templates reference assets
-// through assetURL, which appends the hash as ?v=…, so a versioned URL names
-// one exact file content and can be cached forever; a rebuilt asset gets a
-// new URL.
-var assetVersions = hashAssets()
-
-func hashAssets() map[string]string {
-	versions := map[string]string{}
-	_ = fs.WalkDir(assets, "assets", func(p string, d fs.DirEntry, err error) error {
-		if err != nil || d.IsDir() {
-			return err
-		}
-		b, err := assets.ReadFile(p)
-		if err != nil {
-			return err
-		}
-		sum := sha256.Sum256(b)
-		versions[strings.TrimPrefix(p, "assets/")] = hex.EncodeToString(sum[:])[:12]
-		return nil
-	})
-	return versions
-}
-
-// assetGzip holds a gzip copy of every embedded asset that compresses well,
-// keyed like assetVersions. Built once at startup so serving compressed costs
-// no CPU per request; already-compressed files (fonts) are left out.
-var assetGzip = gzipAssets()
-
-func gzipAssets() map[string][]byte {
-	out := map[string][]byte{}
-	_ = fs.WalkDir(assets, "assets", func(p string, d fs.DirEntry, err error) error {
-		if err != nil || d.IsDir() {
-			return err
-		}
-		b, err := assets.ReadFile(p)
-		if err != nil {
-			return err
-		}
-		var buf bytes.Buffer
-		zw, _ := gzip.NewWriterLevel(&buf, gzip.BestCompression)
-		zw.Write(b)
-		zw.Close()
-		// Not worth a Content-Encoding round trip unless it saves ≥10%.
-		if buf.Len() < len(b)*9/10 {
-			out[strings.TrimPrefix(p, "assets/")] = buf.Bytes()
-		}
-		return nil
-	})
-	return out
-}
-
-// acceptsGzip reports whether the client accepts a gzip response body.
-func acceptsGzip(r *http.Request) bool {
-	for _, enc := range strings.Split(r.Header.Get("Accept-Encoding"), ",") {
-		enc, q, _ := strings.Cut(strings.TrimSpace(enc), ";")
-		if strings.TrimSpace(enc) == "gzip" && strings.ReplaceAll(q, " ", "") != "q=0" {
-			return true
-		}
-	}
-	return false
-}
-
-// assetURL is the "asset" template func: {{asset "style.css"}} renders
-// /_/style.css?v=<hash>. An unknown name fails the template so a typo or a
-// removed file surfaces as a render error instead of a silent 404.
-func assetURL(name string) (string, error) {
-	v, ok := assetVersions[name]
-	if !ok {
-		return "", fmt.Errorf("unknown asset %q", name)
-	}
-	return "/_/" + name + "?v=" + v, nil
-}
-
-// assetFuncs is for the standalone fragment templates that do not take the
-// full tmplFuncs.
-var assetFuncs = template.FuncMap{"asset": assetURL}
-
-// serveStatic serves the embedded assets under /_/. Embedded files carry no
-// modtime, so http.FileServer alone sends no validators and browsers refetch
-// every asset on every page. Instead:
-//   - a URL carrying the current ?v= hash is immutable;
-//   - fonts are immutable too (referenced unversioned from style.css, never
-//     change);
-//   - anything else (unversioned or stale ?v=, e.g. icons from CSS) gets the
-//     content hash as ETag and revalidates, answered with 304 when unchanged.
-//
-// Assets with a precompressed copy (see assetGzip) are sent gzipped to
-// clients that accept it; the gzip variant gets its own ETag.
-func serveStatic() http.Handler {
-	staticFS, _ := fs.Sub(assets, "assets")
-	static := http.StripPrefix("/_/", http.FileServer(http.FS(staticFS)))
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		name := strings.TrimPrefix(r.URL.Path, "/_/")
-		v, ok := assetVersions[name]
-		gz, hasGz := assetGzip[name]
-		useGz := hasGz && acceptsGzip(r)
-		if hasGz {
-			w.Header().Set("Vary", "Accept-Encoding")
-		}
-		switch {
-		case ok && r.URL.Query().Get("v") == v, strings.HasPrefix(name, "fonts/"):
-			w.Header().Set("Cache-Control", "public, max-age=31536000, immutable")
-		case ok:
-			w.Header().Set("Cache-Control", "no-cache")
-			if useGz {
-				w.Header().Set("ETag", `"`+v+`-gz"`)
-			} else {
-				w.Header().Set("ETag", `"`+v+`"`)
-			}
-		}
-		if useGz {
-			w.Header().Set("Content-Encoding", "gzip")
-			// ServeContent derives Content-Type from the name's extension.
-			http.ServeContent(w, r, name, time.Time{}, bytes.NewReader(gz))
-			return
-		}
-		static.ServeHTTP(w, r)
-	})
-}

static_test.go

@@ -1,111 +0,0 @@
-package main
-
-import (
-	"bytes"
-	"compress/gzip"
-	"io"
-	"io/fs"
-	"net/http"
-	"net/http/httptest"
-	"regexp"
-	"strings"
-	"testing"
-)
-
-// Every {{asset "…"}} in the templates must name an embedded file, or the page
-// fails to render.
-func TestTemplateAssetsExist(t *testing.T) {
-	ref := regexp.MustCompile(`\{\{asset "([^"]+)"\}\}`)
-	_ = fs.WalkDir(assets, "assets", func(p string, d fs.DirEntry, err error) error {
-		if err != nil || d.IsDir() {
-			return err
-		}
-		b, _ := assets.ReadFile(p)
-		for _, m := range ref.FindAllSubmatch(b, -1) {
-			if _, err := assetURL(string(m[1])); err != nil {
-				t.Errorf("%s: %v", p, err)
-			}
-		}
-		return nil
-	})
-}
-
-func TestServeStaticCaching(t *testing.T) {
-	h := serveStatic()
-	get := func(url, ifNoneMatch string) *httptest.ResponseRecorder {
-		r := httptest.NewRequest(http.MethodGet, url, nil)
-		if ifNoneMatch != "" {
-			r.Header.Set("If-None-Match", ifNoneMatch)
-		}
-		w := httptest.NewRecorder()
-		h.ServeHTTP(w, r)
-		return w
-	}
-	v := assetVersions["style.css"]
-
-	versioned, _ := assetURL("style.css")
-	if w := get(versioned, ""); w.Code != 200 || w.Header().Get("Cache-Control") != "public, max-age=31536000, immutable" {
-		t.Errorf("versioned: %d %q", w.Code, w.Header().Get("Cache-Control"))
-	}
-	for _, u := range []string{"/_/style.css", "/_/style.css?v=stale"} {
-		w := get(u, "")
-		if w.Code != 200 || w.Header().Get("Cache-Control") != "no-cache" || w.Header().Get("ETag") != `"`+v+`"` {
-			t.Errorf("%s: %d %q %q", u, w.Code, w.Header().Get("Cache-Control"), w.Header().Get("ETag"))
-		}
-	}
-	if w := get("/_/style.css", `"`+v+`"`); w.Code != http.StatusNotModified {
-		t.Errorf("revalidate: got %d, want 304", w.Code)
-	}
-	if w := get("/_/fonts/IosevkaSlab.woff2", ""); w.Header().Get("Cache-Control") != "public, max-age=31536000, immutable" {
-		t.Errorf("font: %q", w.Header().Get("Cache-Control"))
-	}
-}
-
-func TestServeStaticGzip(t *testing.T) {
-	h := serveStatic()
-	get := func(url, acceptEncoding, ifNoneMatch string) *httptest.ResponseRecorder {
-		r := httptest.NewRequest(http.MethodGet, url, nil)
-		if acceptEncoding != "" {
-			r.Header.Set("Accept-Encoding", acceptEncoding)
-		}
-		if ifNoneMatch != "" {
-			r.Header.Set("If-None-Match", ifNoneMatch)
-		}
-		w := httptest.NewRecorder()
-		h.ServeHTTP(w, r)
-		return w
-	}
-	want, _ := assets.ReadFile("assets/style.css")
-
-	w := get("/_/style.css", "gzip, deflate, br", "")
-	if w.Code != 200 || w.Header().Get("Content-Encoding") != "gzip" || w.Header().Get("Vary") != "Accept-Encoding" {
-		t.Fatalf("gzip: %d %q %q", w.Code, w.Header().Get("Content-Encoding"), w.Header().Get("Vary"))
-	}
-	if ct := w.Header().Get("Content-Type"); !strings.HasPrefix(ct, "text/css") {
-		t.Errorf("content-type: %q", ct)
-	}
-	zr, err := gzip.NewReader(w.Body)
-	if err != nil {
-		t.Fatal(err)
-	}
-	got, _ := io.ReadAll(zr)
-	if !bytes.Equal(got, want) {
-		t.Errorf("gzip body does not decompress to style.css")
-	}
-
-	etag := w.Header().Get("ETag")
-	if w := get("/_/style.css", "gzip", etag); w.Code != http.StatusNotModified {
-		t.Errorf("gzip revalidate: got %d, want 304", w.Code)
-	}
-
-	for _, ae := range []string{"", "identity", "gzip;q=0"} {
-		w := get("/_/style.css", ae, "")
-		if w.Header().Get("Content-Encoding") != "" || !bytes.Equal(w.Body.Bytes(), want) {
-			t.Errorf("Accept-Encoding %q: got encoding %q", ae, w.Header().Get("Content-Encoding"))
-		}
-	}
-
-	if w := get("/_/fonts/IosevkaSlab.woff2", "gzip", ""); w.Header().Get("Content-Encoding") != "" {
-		t.Errorf("font should not be re-compressed")
-	}
-}

thumb.go

@@ -12,7 +12,6 @@ import (
 	"os"
 	"path"
 	"path/filepath"
-	"runtime"
 	"strconv"
 	"strings"
 	"sync"
@@ -49,13 +48,8 @@ var (
 	thumbLocks   = map[string]*sync.Mutex{}
 	thumbLocksMu sync.Mutex
 
-	digestCache   = map[string]digestEntry{}
+	digestCache  = map[string]digestEntry{}
 	digestCacheMu sync.Mutex
-
-	// thumbGenSlots bounds concurrent thumbnail generation. A grid of uncached
-	// photos otherwise decodes one full-size image per browser connection at
-	// once, which on the NAS means memory pressure and CPU thrash.
-	thumbGenSlots = make(chan struct{}, runtime.NumCPU())
 )
 
 // digestEntry remembers the digest of a source file so repeated requests do
@@ -185,10 +179,7 @@ func (h *handler) serveThumbnail(w http.ResponseWriter, r *http.Request, srcFS s
 		return
 	}
 
-	thumbGenSlots <- struct{}{}
+	if err := generateThumb(cacheFS, write); err != nil {
-	err = generateThumb(cacheFS, write)
-	<-thumbGenSlots
-	if err != nil {
 		log.Printf("thumb %s: %v", rel, err)
 		http.Error(w, "thumbnail failed", http.StatusInternalServerError)
 		return
@@ -208,9 +199,6 @@ func pathDigest(srcFS string, info os.FileInfo) string {
 // On a cache hit (path + mtime + size unchanged) the returned data is nil,
 // so the caller knows to open the file itself. On a miss the file is read
 // once and the contents are returned for the caller to reuse.
-//
-// Hits come from memory or, after a restart, from the on-disk index (see
-// digestIndexPath), so an unchanged file is hashed only once ever.
 func sourceDigest(srcFS string, info os.FileInfo) (string, []byte, error) {
 	digestCacheMu.Lock()
 	d, ok := digestCache[srcFS]
@@ -219,43 +207,18 @@ func sourceDigest(srcFS string, info os.FileInfo) (string, []byte, error) {
 		return d.hex, nil, nil
 	}
 
-	indexFS := digestIndexPath(srcFS, info)
-	if b, err := os.ReadFile(indexFS); err == nil && len(b) == sha256.Size*2 {
-		h := string(b)
-		rememberDigest(srcFS, info, h)
-		return h, nil, nil
-	}
-
 	data, err := os.ReadFile(srcFS)
 	if err != nil {
 		return "", nil, err
 	}
 	sum := sha256.Sum256(data)
 	h := hex.EncodeToString(sum[:])
-	rememberDigest(srcFS, info, h)
 
-	// Best effort: a failed write only costs a re-hash after the next restart.
-	if err := os.MkdirAll(filepath.Dir(indexFS), 0755); err == nil {
-		if err := writeFileAtomic(indexFS, []byte(h), 0644); err != nil {
-			log.Printf("thumb digest index %s: %v", indexFS, err)
-		}
-	}
-	return h, data, nil
-}
-
-// digestIndexPath is where the content digest of srcFS is persisted, keyed on
-// path + mtime + size like pathDigest, so overwriting the file misses and
-// re-hashes. Entries for changed or deleted files are left behind; each is 64
-// bytes.
-func digestIndexPath(srcFS string, info os.FileInfo) string {
-	key := pathDigest(srcFS, info)
-	return filepath.Join(thumbCacheDir, "digests", key[:2], key)
-}
-
-func rememberDigest(srcFS string, info os.FileInfo, h string) {
 	digestCacheMu.Lock()
 	digestCache[srcFS] = digestEntry{mtime: info.ModTime(), size: info.Size(), hex: h}
 	digestCacheMu.Unlock()
+
+	return h, data, nil
 }
 
 func serveThumb(w http.ResponseWriter, r *http.Request, cacheFS string) {

thumb_image.go

@@ -57,14 +57,6 @@ func resizeBox(src image.Image, width int) image.Image {
 	}
 	dst := image.NewRGBA(image.Rect(0, 0, dstW, dstH))
 
-	// JPEGs decode to *image.YCbCr. Reading its planes directly avoids an
-	// interface call and a colour conversion per source pixel, which makes the
-	// resize ~4x faster; everything else takes the generic At() path.
-	avg := boxAvg
-	if ycc, ok := src.(*image.YCbCr); ok {
-		avg = func(_ image.Image, r image.Rectangle) color.RGBA { return boxAvgYCbCr(ycc, r) }
-	}
-
 	for y := 0; y < dstH; y++ {
 		sy0 := y * srcH / dstH
 		sy1 := (y + 1) * srcH / dstH
@@ -77,42 +69,23 @@ func resizeBox(src image.Image, width int) image.Image {
 			if sx1 == sx0 {
 				sx1 = sx0 + 1
 			}
-			box := image.Rect(sx0, sy0, sx1, sy1).Add(b.Min)
+			var r, g, bl, n uint64
-			dst.SetRGBA(x, y, avg(src, box))
+			for sy := sy0; sy < sy1; sy++ {
+				for sx := sx0; sx < sx1; sx++ {
+					sr, sg, sb, _ := src.At(b.Min.X+sx, b.Min.Y+sy).RGBA()
+					r += uint64(sr >> 8)
+					g += uint64(sg >> 8)
+					bl += uint64(sb >> 8)
+					n++
+				}
+			}
+			dst.SetRGBA(x, y, color.RGBA{
+				R: uint8(r / n),
+				G: uint8(g / n),
+				B: uint8(bl / n),
+				A: 255,
+			})
 		}
 	}
 	return dst
 }
-
-// boxAvg returns the mean colour of the pixels of src inside r.
-func boxAvg(src image.Image, r image.Rectangle) color.RGBA {
-	var red, g, bl, n uint64
-	for y := r.Min.Y; y < r.Max.Y; y++ {
-		for x := r.Min.X; x < r.Max.X; x++ {
-			sr, sg, sb, _ := src.At(x, y).RGBA()
-			red += uint64(sr >> 8)
-			g += uint64(sg >> 8)
-			bl += uint64(sb >> 8)
-			n++
-		}
-	}
-	return color.RGBA{R: uint8(red / n), G: uint8(g / n), B: uint8(bl / n), A: 255}
-}
-
-// boxAvgYCbCr is boxAvg for *image.YCbCr, reading the sample planes directly.
-// Each pixel is still converted to RGB before averaging so out-of-gamut
-// samples clamp exactly as they do through At().
-func boxAvgYCbCr(src *image.YCbCr, r image.Rectangle) color.RGBA {
-	var red, g, bl, n uint64
-	for y := r.Min.Y; y < r.Max.Y; y++ {
-		for x := r.Min.X; x < r.Max.X; x++ {
-			ci := src.COffset(x, y)
-			sr, sg, sb := color.YCbCrToRGB(src.Y[src.YOffset(x, y)], src.Cb[ci], src.Cr[ci])
-			red += uint64(sr)
-			g += uint64(sg)
-			bl += uint64(sb)
-			n++
-		}
-	}
-	return color.RGBA{R: uint8(red / n), G: uint8(g / n), B: uint8(bl / n), A: 255}
-}

thumb_image_test.go

@@ -1,89 +0,0 @@
-package main
-
-import (
-	"bytes"
-	"image"
-	"image/jpeg"
-	"os"
-	"path/filepath"
-	"testing"
-)
-
-// testPhoto returns a JPEG-decoded (so *image.YCbCr, 4:2:0) image with an odd
-// size and a non-zero origin to exercise the plane offset arithmetic.
-func testPhoto(t testing.TB, w, h int) *image.YCbCr {
-	t.Helper()
-	src := image.NewRGBA(image.Rect(0, 0, w, h))
-	for i := range src.Pix {
-		src.Pix[i] = uint8(i*7 + i/w)
-	}
-	var buf bytes.Buffer
-	if err := jpeg.Encode(&buf, src, &jpeg.Options{Quality: 90}); err != nil {
-		t.Fatal(err)
-	}
-	img, err := jpeg.Decode(&buf)
-	if err != nil {
-		t.Fatal(err)
-	}
-	return img.(*image.YCbCr).SubImage(image.Rect(3, 5, w, h)).(*image.YCbCr)
-}
-
-func TestResizeBoxYCbCrMatchesGeneric(t *testing.T) {
-	src := testPhoto(t, 1001, 667)
-	fast := resizeBox(src, 120).(*image.RGBA)
-	// Hide the concrete type so resizeBox takes the generic At() path.
-	slow := resizeBox(struct{ image.Image }{src}, 120).(*image.RGBA)
-	if fast.Bounds() != slow.Bounds() {
-		t.Fatalf("bounds %v != %v", fast.Bounds(), slow.Bounds())
-	}
-	for i := range fast.Pix {
-		if fast.Pix[i] != slow.Pix[i] {
-			t.Fatalf("pixel byte %d: fast %d, generic %d", i, fast.Pix[i], slow.Pix[i])
-		}
-	}
-}
-
-func BenchmarkResizeBox(b *testing.B) {
-	src := testPhoto(b, 4000, 3000)
-	b.Run("ycbcr", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
-			resizeBox(src, 300)
-		}
-	})
-	b.Run("generic", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
-			resizeBox(struct{ image.Image }{src}, 300)
-		}
-	})
-}
-
-// After a restart (empty memory cache) the digest comes from the on-disk index
-// without reading the source file.
-func TestSourceDigestPersists(t *testing.T) {
-	old := thumbCacheDir
-	thumbCacheDir = t.TempDir()
-	t.Cleanup(func() { thumbCacheDir = old })
-
-	src := filepath.Join(t.TempDir(), "a.jpg")
-	if err := os.WriteFile(src, []byte("photo"), 0644); err != nil {
-		t.Fatal(err)
-	}
-	info, _ := os.Stat(src)
-	h1, data, err := sourceDigest(src, info)
-	if err != nil || data == nil {
-		t.Fatalf("first call: %v, data=%v", err, data)
-	}
-
-	digestCacheMu.Lock()
-	delete(digestCache, src)
-	digestCacheMu.Unlock()
-	// Removing the source proves the second call does not read it again.
-	if err := os.Remove(src); err != nil {
-		t.Fatal(err)
-	}
-
-	h2, data, err := sourceDigest(src, info)
-	if err != nil || data != nil || h2 != h1 {
-		t.Fatalf("after restart: h=%s data=%v err=%v, want %s from index", h2, data, err, h1)
-	}
-}

tree.go

@@ -12,10 +12,6 @@ import (
 type treeEntry struct {
 	Name string `json:"name"`
 	Kind string `json:"kind"`
-	// HasChildren reports whether a folder has any visible entries (under the
-	// same foldersOnly filter), so the client can hide the expand chevron on
-	// empty folders without a round-trip. Always false for files.
-	HasChildren bool `json:"hasChildren"`
 	// Children is populated only along the expandTo chain (see handleTree);
 	// omitted otherwise so the flat picker listing keeps its original shape.
 	Children []treeEntry `json:"children,omitempty"`
@@ -85,11 +81,7 @@ func listTreeEntries(fsPath string, foldersOnly bool) ([]treeEntry, error) {
 			continue
 		}
 		if e.IsDir() {
-			folders = append(folders, treeEntry{
+			folders = append(folders, treeEntry{Name: name, Kind: "folder"})
-				Name:        name,
-				Kind:        "folder",
-				HasChildren: folderHasChildren(filepath.Join(fsPath, name), foldersOnly),
-			})
 		} else {
 			if foldersOnly || name == "index.md" {
 				continue
@@ -102,33 +94,6 @@ func listTreeEntries(fsPath string, foldersOnly bool) ([]treeEntry, error) {
 	return append(folders, files...), nil
 }
 
-// folderHasChildren reports whether fsPath contains at least one entry that
-// listTreeEntries would list. It reads the directory in small batches and
-// stops at the first match, so large folders stay cheap. Unreadable folders
-// report false.
-func folderHasChildren(fsPath string, foldersOnly bool) bool {
-	f, err := os.Open(fsPath)
-	if err != nil {
-		return false
-	}
-	defer f.Close()
-	for {
-		batch, err := f.ReadDir(32)
-		for _, e := range batch {
-			name := e.Name()
-			if strings.HasPrefix(name, ".") {
-				continue
-			}
-			if e.IsDir() || (!foldersOnly && name != "index.md") {
-				return true
-			}
-		}
-		if err != nil {
-			return false
-		}
-	}
-}
-
 // treePathSegments splits a wiki path into its non-empty segments.
 func treePathSegments(p string) []string {
 	var segs []string