feat(analytics): add Umami event tracking utilities

- Add comprehensive analytics.ts with type-safe event tracking
- Include app-specific event helpers (Auth, Landing, Chat, Picture, Todo, Calendar, Clock, Contacts, ManaDeck, Subscription, App events)
- Export from shared-utils package
- Add complete documentation in docs/ANALYTICS.md

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/shared-utils/src/index.ts

@@ -25,3 +25,6 @@ export * from './cache';
 
 // Natural Language Parsers
 export * from './parsers';
+
+// Umami Analytics
+export * from './analytics';