feat: add local fallback for S3 writes

src/api/admin_storage.rs

@@ -60,6 +60,8 @@ struct StorageEndpointView {
 #[derive(Debug, Serialize)]
 struct StorageEndpointsResponse {
     active_backend: String,
+    local_object_count: i64,
+    local_stored_bytes: i64,
     endpoints: Vec<StorageEndpointView>,
 }
 
@@ -109,6 +111,7 @@ async fn list_storage_endpoints(
     } else {
         "local"
     };
+    let (local_object_count, local_stored_bytes) = local_usage(&state).await?;
     let mut views = Vec::with_capacity(endpoints.len());
     for endpoint in endpoints {
         views.push(endpoint_view(&state, endpoint).await?);
@@ -118,6 +121,8 @@ async fn list_storage_endpoints(
         success: true,
         data: StorageEndpointsResponse {
             active_backend: active_backend.to_string(),
+            local_object_count,
+            local_stored_bytes,
             endpoints: views,
         },
     }))
@@ -536,6 +541,28 @@ async fn endpoint_usage(state: &AppState, endpoint_id: Uuid) -> Result<(i64, i64
     .map_err(|err| AppError::new(ErrorCode::Internal, "统计存储使用量失败").with_source(err))
 }
 
+async fn local_usage(state: &AppState) -> Result<(i64, i64), AppError> {
+    sqlx::query_as::<_, (i64, i64)>(
+        r#"
+        SELECT
+          (SELECT COUNT(*) FROM task_files
+             WHERE status = 'completed'
+               AND storage_backend = 'local'
+               AND COALESCE(storage_key, storage_path) IS NOT NULL)
+            + (SELECT COUNT(*) FROM tasks
+                 WHERE zip_storage_backend = 'local'
+                   AND zip_storage_key IS NOT NULL) AS object_count,
+          COALESCE((SELECT SUM(compressed_size)::BIGINT FROM task_files
+                      WHERE status = 'completed' AND storage_backend = 'local'), 0::BIGINT)
+            + COALESCE((SELECT SUM(zip_size)::BIGINT FROM tasks
+                          WHERE zip_storage_backend = 'local'), 0::BIGINT) AS stored_bytes
+        "#,
+    )
+    .fetch_one(&state.db)
+    .await
+    .map_err(|err| AppError::new(ErrorCode::Internal, "统计本地存储使用量失败").with_source(err))
+}
+
 async fn record_test_result(
     state: &AppState,
     endpoint_id: Uuid,