fix: 7-61 tester-reported bugs — extensions panel HTML nesting, search 422, unexported functions

Fixes for 06327d59 regressions:

1. Extensions tab invisible: global panel missing closing tag, extensions panel nested inside hidden global section
2. Search test 422: performKnowledgeRagSearch missing workspaceId/rootUri/sourceKind in request body
3. Search params broken: loadKnowledgeRagSearchParamsToForm and syncKnowledgeRagThresholdDisplay not exported from settings runtime

835/838 Rust tests pass (3 pre-existing failures)

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

@@ -594,6 +594,7 @@ export function createSidebarPageSettingsRuntime(context) {
         '<div class="wolai-page-settings-section" data-page-settings-panel="global" hidden>' +
           createGlobalHeadingNumbersRow() +
           createPageWidthRows() +
+        '</div>' +
         '<div class="wolai-page-settings-section mnote-extensions-panel" data-page-settings-panel="extensions" hidden>' +
           '<div class="mnote-extensions-subtabs" role="tablist" aria-label="扩展子面板">' +
             '<button type="button" class="mnote-extensions-subtab is-active" role="tab" aria-selected="true" data-extensions-subtab="knowledge">知识库</button>' +
@@ -614,7 +615,6 @@ export function createSidebarPageSettingsRuntime(context) {
             '<div class="mnote-extensions-status" data-extensions-status="tools"><span class="mnote-extensions-loading">加载中...</span></div>' +
           '</div>' +
         '</div>' +
-        '</div>' +
         '<div class="wolai-page-settings-section mnote-dashboard-panel" data-page-settings-panel="dashboard" hidden>' +
           '<div class="mnote-dashboard-grid">' +
             '<div class="mnote-dashboard-card" data-dashboard-card="knowledge">' +
@@ -2009,10 +2009,18 @@ export function createSidebarPageSettingsRuntime(context) {
       params.set('query', query);
       params.set('mode', currentKnowledgeRagSearchParams().mode || 'hybrid');
       params.set('top_k', String(currentKnowledgeRagSearchParams().top_k || 10));
+      // 获取当前 workspace 上下文
+      var workspaceId = resolveWorkspaceId(document.body) || '';
+      var rootUri = currentRootUri ? currentRootUri() : '';
+      var sourceKind = currentSourceKind ? currentSourceKind() : '';
+      var body = { query: query };
+      if (workspaceId) body.workspaceId = workspaceId;
+      if (rootUri) body.rootUri = rootUri;
+      if (sourceKind) body.sourceKind = sourceKind;
       var resp = await fetch('/api/knowledge-rag/search?' + params.toString(), {
         method: 'POST',
         headers: { 'content-type': 'application/json' },
-        body: JSON.stringify({ query: query })
+        body: JSON.stringify(body)
       });
       if (!resp.ok) throw new Error('HTTP ' + resp.status);
       var data = await resp.json();
@@ -2657,9 +2665,11 @@ export function createSidebarPageSettingsRuntime(context) {
     ingestSingleKnowledgeRagSource,
     loadKnowledgeRagStatus,
     openKnowledgeRagDashboard,
+    loadKnowledgeRagSearchParamsToForm,
     performKnowledgeRagSearch,
     saveKnowledgeRagSearchParams,
     setActiveKnowledgeRagDetailTab,
+    syncKnowledgeRagThresholdDisplay,
 
     pruneKnowledgeRagRegistry,
     removeKnowledgeRagSourceInput,