feat(apps): add unified Apps page and PillNavigation to all web apps

- Add AppsPage component to shared-ui for displaying all Mana apps
- Add allAppsHref prop to PillNavigation with "Alle Apps" link in dropdown
- Integrate PillNavigation in archived apps (maerchenzauber, news, uload, wisekeep)
- Add /apps route to all web apps (active and archived)
- Replace custom sidebars/headers with unified PillNavigation

Apps updated:
- Active: chat, manacore, manadeck, picture, presi, zitare
- Archived: maerchenzauber, memoro, news, nutriphi, uload, wisekeep

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

packages/shared-ui/src/index.ts

@@ -58,3 +58,6 @@ export {
 	SettingsDangerZone,
 	SettingsDangerButton,
 } from './settings';
+
+// Pages
+export { default as AppsPage } from './pages/AppsPage.svelte';