fix: P0-5 — upload-status rollback, streaming copy (LOCAL only), user re-verify, honest lock

B1: `_mark_upload_failed_and_raise` now commits on a separate session
  - Helper takes `request + upload_id`, opens a fresh session from
    `request.app.state.session_factory` and commits there before raising.
  - Closes the named-lock connection-pool leak Codex flagged: the old
    "commit-on-the-same-session" implementation could return the
    GET_LOCK connection to the pool before the enclosing
    `finally: release_named_lock` ran, leaking `mp:<hash>` for up to
    `pool_recycle` and re-opening the same-key upload race.
  - Same helper now used by `create_server_object_payload`'s put-failure
    branch — two failure paths have identical semantics.

B2: streaming copy for soft-delete + restore (`get_stream() + put()`)
  - LOCAL backend: zero-copy (aiofiles stream write). OOM fixed.
  - S3 backend: still OOMs on multi-GB objects — `put()` materializes
    the async iter via `b"".join(chunks)`. Multipart `put` is a
    follow-up; do NOT claim "OOM fixed on production" since production
    defaults to S3.

C1: worker re-verifies `Users.status='active' AND is_deleted=0`
  - `_assert_user_active` called from `_execution_context` after
    resolving `triggered_by`; skips `SYSTEM_CRON_USER_ID`.
  - `USER_DISABLED` error_code goes into the `NODE_FINISHED_EVENT`
    outbox payload — `schedule_node_runs` has no `error_code` column,
    the row only carries the `message` text. Docstrings corrected to
    say so explicitly (previous docstring falsely promised row-level
    observability).

F1: honest browser-local file lock
  - `api.ts` `acquireFileLock/heartbeatFileLock/releaseFileLock/
    releaseFileLockOnUnload` are now no-ops with comments stating they
    never call the network.
  - `scriptWorkspaceStore` dropped `tickHeartbeats`; `tickCleanup`
    simplified to just clear cache.
  - `useEditSessionLifecycle` dropped its 15s heartbeat `setInterval`.
  - `ScriptWorkspace.tsx` renders `.local-lock-banner` info bar when
    `isEditing`. Two tabs may still silently last-write — banner is the
    only guard (acceptable disclosure-only tradeoff).

Dead code: deleted the duplicate `upload_bytes_to_session` in
`backend/src/backend/storage_api.py`. The `services.storage` import
is now the only source of the function; `create_upload_record`'s
docstring updated to point at `backend.resources`.

frontend/app/features/platform/ScriptWorkspace.tsx

@@ -478,6 +478,18 @@ export function ScriptWorkspace({
         )}
       </div>
 
+      {/* 本地编辑锁提示——只在非 Python 编辑时显示，
+          因为 Python 编辑走 pythonEditorBuffers，不走文件锁。
+          这个锁只在本浏览器当前 tab 内有效，不能阻止隐身模式 / 其它浏览器同时编辑。 */}
+      {isEditing && (
+        <div className="local-lock-banner">
+          <Icon name="info" size={14} />
+          <span>
+            本地编辑锁——关闭标签页、刷新页面或换浏览器后失效，不会阻止他人同时编辑。
+          </span>
+        </div>
+      )}
+
       {/* 编辑器画布区域 - 始终渲染，保证 iframe 不重新加载 */}
       <div className="editor-canvas-wrapper" style={{ position: 'relative', width: '100%', height: '100%', overflow: 'hidden' }}>
         {/* 只读模式内容 - 用 CSS 控制显示/隐藏 */}

frontend/app/features/platform/hooks/useEditSessionLifecycle.ts

@@ -9,8 +9,9 @@ type ActivePage = "home" | "scripts" | "schedules" | "system";
 
 /**
  * 必须在 layout 层挂载，不能放在 ScriptsPage。
- * 原因：心跳 / cleanup / beforeunload 需要在用户切到 /schedules 时仍运行，
- * 否则其他 tab 中的编辑会话锁会过期。
+ * 原因：cleanup / beforeunload 需要在用户切到 /schedules 时仍运行，否则跨页
+ * 浏览 10 分钟以上再回来时，sessionCache 里塞的全是陈旧的本地锁。
+ * 心跳已删除——本地锁没有过期概念，存不存在 15s 定时器都一样。
  */
 export function useEditSessionLifecycle({
   activePage,
@@ -26,17 +27,9 @@ export function useEditSessionLifecycle({
     void useScriptWorkspaceStore.getState().endEditing(true, false);
   }, [activePage]);
 
-  // 2) 心跳 + cleanup 定时器（15s 心跳，60s 检查 cleanup）
+  // 2) 本地缓存回收（60s 检查一次，10 分钟无活动的本地锁清掉）
   useEffect(() => {
-    let heartbeatRunning = false;
     let cleanupRunning = false;
-    const heartbeatTimer = window.setInterval(() => {
-      if (heartbeatRunning) return;
-      heartbeatRunning = true;
-      void useScriptWorkspaceStore.getState().tickHeartbeats().finally(() => {
-        heartbeatRunning = false;
-      });
-    }, 15 * 1000);
     const cleanupTimer = window.setInterval(() => {
       if (cleanupRunning) return;
       cleanupRunning = true;
@@ -47,12 +40,11 @@ export function useEditSessionLifecycle({
       }
     }, 60 * 1000);
     return () => {
-      window.clearInterval(heartbeatTimer);
       window.clearInterval(cleanupTimer);
     };
   }, []);
 
-  // 3) 卸载前释放编辑锁
+  // 3) 卸载前清理本地锁引用（详见 store.releaseActiveOnUnload）
   useEffect(() => {
     const handleUnload = () => {
       useScriptWorkspaceStore.getState().releaseActiveOnUnload();

frontend/app/features/platform/state/scriptWorkspaceStore.ts

@@ -128,7 +128,8 @@ type State = {
   refreshReadOnlyContent: () => void;  // 刷新只读内容
 
   // 生命周期 tick（由 layout 层 useEditSessionLifecycle 周期性调用）
-  tickHeartbeats: () => Promise<void>;
+  // 本地锁无服务端心跳——tickHeartbeats 已删除，保留 tickCleanup 仅用于回收
+  // 闲置 10 分钟以上的本地缓存。
   tickCleanup: () => void;
   releaseActiveOnUnload: () => void;
 };
@@ -1077,57 +1078,9 @@ export const useScriptWorkspaceStore = create<State>((set, get) => {
       }
     },
 
-    tickHeartbeats: async () => {
-      if (!_api) return;
-      // 1) 当前 active session 心跳
-      const active = _editSession;
-      if (active) {
-        try {
-          const updated = await _api.heartbeatFileLock(active);
-          if (
-            _editSession
-            && _editSession.edit_session_id === updated.edit_session_id
-          ) {
-            const merged = {
-              ..._editSession,
-              session_status: updated.session_status,
-              expires_at: updated.expires_at,
-            };
-            _editSession = merged;
-            editSessionHandle.current = merged;
-            set({ editSession: merged });
-          }
-        } catch (error) {
-          _editSession = null;
-          editSessionHandle.current = null;
-          set({ editSession: null, embeddedJupyterUrl: null });
-          pushToast(
-            "error",
-            `编辑锁心跳已中断：${
-              error instanceof Error ? error.message : "请重新打开文件"
-            }`,
-          );
-        }
-      }
-      // 2) 缓存会话心跳（不更新 React state，只更新缓存对象本身）
-      const promises: Promise<void>[] = [];
-      for (const cached of sessionCache.values()) {
-        promises.push(
-          _api.heartbeatFileLock(cached.session)
-            .then((updated) => {
-              cached.session.session_status = updated.session_status;
-              cached.session.expires_at = updated.expires_at;
-            })
-            .catch(() => {
-              // 静默失败：等用户切回来时再处理
-            }),
-        );
-      }
-      await Promise.allSettled(promises);
-    },
-
     tickCleanup: () => {
-      if (!_api) return;
+      // 本地锁：清缓存即可，不要发 releaseFileLock 请求。
+      // 接口是异步的，但在本地实现里等价于无操作，promise 没人 await。
       const TEN_MINUTES = 10 * 60 * 1000;
       const now = Date.now();
       const toCleanup: string[] = [];
@@ -1141,15 +1094,11 @@ export const useScriptWorkspaceStore = create<State>((set, get) => {
       }
       if (toCleanup.length === 0) return;
       for (const scriptId of toCleanup) {
-        const cached = sessionCache.get(scriptId);
-        if (cached) {
-          _api.releaseFileLock(cached.session).catch(console.warn);
-          sessionCache.delete(scriptId);
-        }
+        sessionCache.delete(scriptId);
       }
       pushToast(
         "info",
-        `已清理 ${toCleanup.length} 个长时间未活动的编辑会话`,
+        `已清理 ${toCleanup.length} 个长时间未活动的本地编辑会话`,
       );
     },