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>

CHANGELOG.md

@@ -3,6 +3,24 @@
 All notable changes to CodeCraft. Versions follow [Semantic Versioning](https://semver.org/);
 until 1.0, minor versions may contain breaking changes.
 
+## [Unreleased]
+
+### Added
+
+- **Collapsible task list:** the model's task list above the composer folds to one line
+  (progress and current task) with a click on its heading; the choice is kept per device.
+- **Square and short screens** (e.g. Clicks Communicator, phones in landscape): tighter top bar,
+  composer and new-chat wizard, so the chat keeps most of the height.
+
+### Fixed
+
+- **Blank page on phones after the update:** installed apps (PWA) checked their service worker
+  at its old URL, got the web page instead of a script and therefore kept the previous app
+  version forever. With the new image format of v202611-00010 that old version crashed after
+  showing the chat for a moment. Old service worker URLs now get the clean-up worker, which
+  removes the stale worker and reloads the current version. Missing scripts/styles answer
+  404 instead of the web page.
+
 ## [v202611-00010] – 2026-11-09
 
 ### Changed