- Added BlockUser and UnblockUser methods to SocialService
- Added BlockUser and UnblockUser handlers in ProfileHandler
- Added routes: POST /users/:id/block and DELETE /users/:id/block
- Handlers use existing SocialService methods
- Includes validation to prevent users from blocking themselves
- Added IsBlocked helper method to check block status
- Handlers use standard API response format
Phase: PHASE-2
Priority: P2
Progress: 27/267 (10.1%)
