Add Calendar integration (read-only)

assets/calendar/page.html

@@ -0,0 +1,45 @@
+<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}}