feat(quota): implement workspace-level quota enforcement and statistics

- Refactor quota management logic to support usage checks scoped by workspace.
- Update quota statistics API to return granular quota details for each workspace.
- Revise default configuration settings for terminal user and model limits.
- Remove quota check decorators from the model controller.

api/app/controllers/app_controller.py

@@ -1286,7 +1286,7 @@ async def import_app(
     # 仅新建应用时检查配额，覆盖已有应用时跳过
     if target_app_id is None:
         from app.core.quota_manager import _check_quota
-        _check_quota(db, current_user.tenant_id, "app_quota", "app")
+        _check_quota(db, current_user.tenant_id, "app_quota", "app", workspace_id=current_user.current_workspace_id)
     result_app, warnings = AppDslService(db).import_dsl(
         dsl=dsl,
         workspace_id=current_user.current_workspace_id,