Fix stale PWA service worker after updates; collapsible task list; short screens

Installed apps checked their service worker at /sw-<old build>.js. That file no
longer exists after an update and the static fallback answered with index.html,
so the update check failed and the old worker kept serving the previous app
shell. The old frontend crashed on the new image references (base64Size of a
missing `data`), leaving a blank page on phones. Old service worker URLs now get
the clean-up worker (/sw.js), which unregisters and reloads; missing scripts and
styles answer 404 instead of HTML.

- Task list above the composer folds to one line (progress, current task),
  remembered per device.
- max-height: 560px layout (square phones such as the Clicks Communicator,
  landscape): tighter top bar, composer and new-chat wizard.

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

web/src/whatsnew.ts

@@ -3,6 +3,10 @@
  * under "unreleased"; scripts/release.sh renames the key to the release version.
  */
 export const WHATS_NEW: Record<string, { en: string[]; de: string[] }> = {
+  unreleased: {
+    en: ["The task list of the model can be folded (click on \"Tasks\")", "Better layout on square and short screens (e.g. Clicks Communicator, landscape)"],
+    de: ["Die Aufgabenliste des Modells lässt sich zuklappen (Klick auf „Aufgaben“)", "Besseres Layout auf quadratischen und niedrigen Displays (z. B. Clicks Communicator, Querformat)"],
+  },
   "202611-00010": {
     en: ["Chats with many images (screenshots, generated images) open much faster – images load when they scroll into view"],
     de: ["Chats mit vielen Bildern (Screenshots, generierte Bilder) öffnen viel schneller – Bilder laden erst beim Hinscrollen"],