fix: stabilize local OCR and prod startup

rust/crates/mnote-web/browser/sidebar-page-settings-runtime.js

@@ -961,8 +961,28 @@ export function createSidebarPageSettingsRuntime(context) {
     }
   }
 
+  function emitLocalIndexBackgroundTask(status, label, error) {
+    var now = Date.now();
+    window.dispatchEvent(new CustomEvent('mnote:local-background-task-updated', {
+      detail: {
+        task: {
+          taskKind: 'local_index',
+          taskId: 'local-index',
+          sourceRootRelativePath: '本地索引',
+          rootUri: currentRootUri(),
+          status: status,
+          stageLabel: label,
+          updatedAtMs: now,
+          finishedAtMs: status === 'running' ? null : now,
+          error: error || null
+        }
+      }
+    }));
+  }
+
   async function refreshLocalIndex() {
     if (!pageSettingsLocalIndexIsAvailable()) return;
+    emitLocalIndexBackgroundTask('running', '本地索引重建中', null);
     pageUiState.localIndexSummary = Object.assign({}, pageUiState.localIndexSummary || {}, {
       scopeKey: pageSettingsLocalIndexScopeKey(),
       loading: true,
@@ -982,8 +1002,10 @@ export function createSidebarPageSettingsRuntime(context) {
       if (!response.ok || !payload || payload.ok !== true) {
         throw new Error(payload && payload.error && payload.error.message ? payload.error.message : 'local_index_refresh_' + response.status);
       }
+      emitLocalIndexBackgroundTask('done', '本地索引已完成', null);
       await loadPageSettingsLocalIndex(true);
     } catch (error) {
+      emitLocalIndexBackgroundTask('failed', '本地索引失败', error instanceof Error ? error.message : String(error));
       pageUiState.localIndexSummary = Object.assign({}, pageUiState.localIndexSummary || {}, {
         scopeKey: pageSettingsLocalIndexScopeKey(),
         loading: false,