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>

apps/chat/apps/web/src/routes/(protected)/+layout.svelte

@@ -205,6 +205,7 @@
 			settingsHref="/settings"
 			manaHref="/mana"
 			profileHref="/profile"
+			allAppsHref="/apps"
 		/>
 
 		<!-- Main Content with dynamic padding based on nav mode -->

apps/chat/apps/web/src/routes/(protected)/apps/+page.svelte

@@ -0,0 +1,14 @@
+<script lang="ts">
+	import { AppsPage } from '@manacore/shared-ui';
+</script>
+
+<div class="apps-page-wrapper">
+	<AppsPage currentAppId="chat" locale="de" title="Alle Apps" />
+</div>
+
+<style>
+	.apps-page-wrapper {
+		background-color: hsl(var(--background));
+		min-height: 100%;
+	}
+</style>