perf(会员): 模型目录与账号权限档并发读取

- load_owner_llm_catalog 原串行等待目录与权限档两次 SpacetimeDB 往返，热路径延迟叠加
- 改为 tokio::join! 并发发起；目录错误仍由 catalog? 返回，权限档失败关闭语义不变

server-rs/crates/api-server/src/llm/mod.rs

@@ -345,13 +345,20 @@ async fn load_llm_catalog(
 }
 
 /// 全局目录 + 账号权限档；所有对外 LLM 路由都经它解析模型。
+///
+/// 两者相互独立，热路径上用 `join!` 并发发往 SpacetimeDB，避免串行叠加两次往返延迟。
 async fn load_owner_llm_catalog(
     state: &AppState,
     owner: &str,
 ) -> Result<OwnerAgcModelCatalog, AppError> {
-    let catalog = load_llm_catalog(state, owner).await?;
-    let access = resolve_owner_agc_model_access(state, owner).await;
-    Ok(OwnerAgcModelCatalog { catalog, access })
+    let (catalog, access) = tokio::join!(
+        load_llm_catalog(state, owner),
+        resolve_owner_agc_model_access(state, owner),
+    );
+    Ok(OwnerAgcModelCatalog {
+        catalog: catalog?,
+        access,
+    })
 }
 
 /// 模型解析错误的统一映射：档位不够是 403 + 专用错误码，目录外 / 停用仍是 422。