fix(permissions): fix 10 high-priority permission system issues

P8: Invalidate all Redis sessions when is_system_admin changes
- Added is_system_admin to UserUpdate schema and UserResponse
- Added invalidate_all_user_sessions call in users.py route
- Added is_system_admin param to user_service.update_user

P9: Remove no-op permission resolution strategies
- Only highest_wins supported, others removed as no-ops
- Updated tenant.py CheckConstraint to only allow highest_wins
- Added KI-Kommentar in permissions.py

P10: Remove legacy check_permission from auth.py
- Removed duplicate check_permission and filter_fields_by_permission
- Fixed ai_copilot_service.py to use permissions.check_permission
- Updated ai_copilot route to pass resolved permissions dict

P11: Verified — no guest_users remnants found

P12: Migrate ContactFolderPermission to EntityPermission
- contact_folder_permission_service now delegates to entity_permission_service
- contact_folder_service uses EntityPermission queries
- Removed ContactFolderPermission from models/__init__.py
- Created migration 0114 to migrate data and drop table

P13: Added RLS migration history comment in alembic/env.py

P14: Verified — services already apply visibility_filter
- saved_filters/views filter by user_id (personal data)
- workspaces are UI context only
- notifications already filter by entity access

P15: Split entity_permission_service.py (932 lines) into 4 modules
- permission_resolver.py: get_effective_access, get_visible_ids, etc.
- permission_cache.py: Redis caching functions
- permission_audit.py: Audit logging helpers
- entity_permission_service.py: CRUD operations + re-exports

P16: Centralize PERM_RANK in permissions.py
- Single source: app.core.permissions.PERM_RANK
- Updated all services to import from permissions.py

P17: Fix MIGRATION_DATABASE_URL to use crm_migration
- docker-compose.yaml defaults changed from crm_user to crm_migration
- .env.docker.example updated
- prestart.sh comment updated

app/services/user_service.py

@@ -151,6 +151,7 @@ class UserService:
         email: str | None = None,
         current_password: str | None = None,
         new_password: str | None = None,
+        is_system_admin: bool | None = None,
     ) -> tuple[User, UserTenant] | None:
         """Update a user and their tenant membership.
 
@@ -181,6 +182,8 @@ class UserService:
             user_tenant.role_id = role_id
         if is_active is not None:
             user.is_active = is_active
+        if is_system_admin is not None:
+            user.is_system_admin = is_system_admin
         if first_name is not None:
             user.first_name = first_name
         if last_name is not None: