v2.5.1 - Hash-Based Authentication Bug Fixes

Fixes:
- Resolved 401 errors on /api/actors endpoint
- Entity save icons now functional on content intelligence page
- Updated all API calls to use omnicore_user_hash
- Comments system works with hash-based auth
- Quick entity creation now functional
- Better error messages for unauthorized users

Technical:
- Actor API now supports hash-based authentication
- Frontend migrated from auth_token to omnicore_user_hash
- Simplified authentication headers across components