feat(ui): add Sentry/GlitchTip, Umami analytics, presign auto-trigger TTS, feedback link

- Add @sentry/sveltekit: server-side init in hooks.server.ts, client-side in
  hooks.client.ts; opt-in via PUBLIC_GLITCHTIP_DSN env var; handleError wired up
- Add Umami analytics: script tag in +layout.svelte (opt-in via PUBLIC_UMAMI_WEBSITE_ID);
  track book_view, chapter_read, audio_played events via window.umami?.track
- Presign audio endpoint now auto-triggers Kokoro TTS generation when audio is
  missing (404 → POST /api/audio → return 202); AudioPlayer handles 202 status
- Fix listAudioCache: was querying non-existent audio_cache collection; now projects
  from audio_jobs where status='done'
- Add Feedback nav link (desktop + mobile + footer) pointing to feedback.libnovel.cc
- Admin scrape page: add full catalogue scrape button; fix retryTask for catalogue
  kind; show retry button for all failed/cancelled tasks regardless of kind

v3/ui/package.json

@@ -29,6 +29,7 @@
 	"dependencies": {
 		"@aws-sdk/client-s3": "^3.1005.0",
 		"@aws-sdk/s3-request-presigner": "^3.1005.0",
+		"@sentry/sveltekit": "^10.45.0",
 		"cropperjs": "^1.6.2",
 		"ioredis": "^5.3.2",
 		"marked": "^17.0.3",