feat(contacts): add duplicate detection, photo upload, and batch operations

- Add duplicate detection service with merge functionality
  - Find duplicates by email, phone, or name
  - Merge contacts with field selection UI
  - Dismiss false positives

- Add contact photo upload
  - Upload photos to MinIO/S3 storage
  - Display photos in all contact views
  - Delete photo functionality

- Add batch operations for multiple contacts
  - Selection mode with checkboxes in all views
  - Batch delete, archive, and favorite actions
  - Fixed-height action bar to prevent layout shifts

- Add multiple contact view modes
  - List view, Grid view, Alphabet view
  - View mode toggle component
  - Sort by first/last name

- Increase avatar sizes across all views

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

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

COMMANDS.md

@@ -8,9 +8,9 @@ pnpm docker:down
 
 pnpm dev:calendar:app
 pnpm dev:todo:full
+pnpm dev:contacts:full
 pnpm dev:chat:app
 pnpm dev:clock:app
-pnpm dev:contacts:app
 pnpm dev:context:app
 pnpm dev:manacore:app # Nur ManaCore Web
 pnpm dev:manacore:backends # Alle 9 Backends für Dashboard-Widgets