Serve delete, move and merge dialogs as htmx fragments

The server renders the dialogs (?dialog=delete|move) and answers a move
that needs confirmation with the merge dialog itself, so the client no
longer builds action URLs or interprets X-Merge-Available. Successful
mutations send HX-Redirect, which hx.js turns into a history replace.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

assets/page/actions.js

@@ -75,45 +75,10 @@ function newPage() {
     });
 }
 
-// submitMove POSTs a move and navigates on success. When the server reports
-// the destination folder already exists but can be merged (the source carries
-// a page and the destination has none), it asks the user to confirm and
-// retries the same move with &merge=1.
-function submitMove(action, target) {
-    fetch(action, { method: 'POST', redirect: 'manual' }).then(function (res) {
-        if (res.type === 'opaqueredirect' || res.ok) {
-            navigateReplace(target);
-            return;
-        }
-        if (res.status === 409 && res.headers.get('X-Merge-Available') === '1') {
-            openModal({
-                title: 'Merge folders?',
-                body: 'The destination folder already exists but has no page of its own. Merge this page and its contents into it?',
-                confirm: {
-                    label: 'MERGE',
-                    onConfirm: function () {
-                        closeModal();
-                        submitMove(action + '&merge=1', target);
-                    }
-                }
-            });
-            return;
-        }
-        return res.text().then(function (msg) {
-            alert(msg || ('Request failed (' + res.status + ')'));
-        });
-    }).catch(function () {
-        alert('Network error');
-    });
-}
-
 function movePage() {
     var current = decodeURIComponent(window.location.pathname).replace(/\/+$/, '');
     if (!current) return;
-    var segs = current.split('/').filter(Boolean);
-    var currentName = segs[segs.length - 1] || '';
-    var parent = '/' + segs.slice(0, -1).join('/');
-    if (parent === '/') parent = '/';
+    var parent = '/' + current.split('/').filter(Boolean).slice(0, -1).join('/');
 
     openTreePicker({
         title: 'Move — new parent?',
@@ -123,53 +88,13 @@ function movePage() {
         hideFiles: true,
         confirmLabel: 'NEXT',
         onSelect: function (newParent) {
-            var input = document.createElement('input');
-            input.type = 'text';
-            input.className = 'input';
-            input.placeholder = 'Page name';
-            input.value = currentName;
-
-            openModal({
-                title: 'Move — new name?',
-                body: input,
-                confirm: {
-                    label: 'MOVE',
-                    onConfirm: function () {
-                        var name = input.value.trim();
-                        if (!name) return;
-                        var dest = (newParent === '/' ? '' : newParent) + '/' + name;
-                        var action = window.location.pathname + '?move=' +
-                            encodeURIComponent(dest);
-                        var target = encodePickedPath(dest) + '/';
-                        closeModal();
-                        submitMove(action, target);
-                    }
-                }
+            // The server renders the name step and handles what follows
+            // (merge confirmation, errors, redirect).
+            closeModal();
+            htmx.ajax('GET', window.location.pathname + '?dialog=move', {
+                target: '#modal-host',
+                values: { parent: newParent }
             });
         }
     });
 }
-
-function deletePage() {
-    var decodedPath = decodeURIComponent(window.location.pathname);
-
-    openModal({
-        title: 'Delete page',
-        body: 'Delete ' + decodedPath + ' and everything inside it?',
-        confirm: {
-            label: 'DELETE',
-            danger: true,
-            enterConfirms: false,
-            onConfirm: function () {
-                var p = window.location.pathname.replace(/\/+$/, '');
-                var idx = p.lastIndexOf('/');
-                var parent = idx > 0 ? p.substring(0, idx + 1) : '/';
-                closeModal();
-                postReplace(window.location.pathname + '?delete=1', null, parent);
-            }
-        },
-        cancel: { autofocus: true },
-        swapButtons: true
-    });
-}
-