refactor: remove backward compatibility layer for permissions

- Delete app/core/permissions.py (VendorPermissions enum, PermissionGroups)
- Update all code to use permission_discovery_service directly:
  - app/api/deps.py: get_user_permissions() uses discovery service
  - app/modules/tenancy/models/vendor.py: get_all_permissions() uses discovery
  - app/modules/tenancy/routes/api/vendor_team.py: use string literals
  - app/modules/tenancy/services/vendor_team_service.py: use discovery service
  - scripts/init_production.py: use discovery service for presets

Permissions are now fully module-driven:
- Each module defines permissions in definition.py
- PermissionDiscoveryService aggregates all permissions
- Role presets reference permission IDs directly

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

app/modules/tenancy/models/vendor.py

@@ -525,10 +525,12 @@ class VendorUser(Base, TimestampMixin):
     def get_all_permissions(self) -> list:
         """Get all permissions this user has."""
         if self.is_owner:
-            # Return all possible permissions
-            from app.core.permissions import VendorPermissions
+            # Return all possible permissions from discovery service
+            from app.modules.tenancy.services.permission_discovery_service import (
+                permission_discovery_service,
+            )
 
-            return list(VendorPermissions.__members__.values())
+            return list(permission_discovery_service.get_all_permission_ids())
 
         if self.role and self.role.permissions:
             return self.role.permissions