UI polish pass: word count, slash commands, task lists, graph peek, bulk delete, export

- WordCount component (toggle words/chars vs read time, persisted mode)
- TipTap: TaskList/TaskItem extensions, slash command menu (H1-H3, lists, code, quote, task)
- Markdown serializer: task list → `- [ ]` / `- [x]` roundtrip
- GraphView: slide-in peek panel for note/task nodes (body, tags, linked nodes); tag nodes still navigate
- ChatView: bulk-select conversations with two-click confirm delete + chat retention policy (default 90d)
- NoteEditorView: pill tab bar with animated edit/preview toggle + WordCount in toolbar
- WorkspaceNoteEditor: inline search with tag matching, inline new-note creation, WordCount
- WorkspaceTaskPanel: task body rendered in slide-over + Edit link
- Settings: data export (Markdown ZIP / JSON) via GET /api/export
- Accessibility: skip-to-content link, aria-labels on all icon-only buttons
- Fix: export route used non-existent fabledassistant.database — corrected to async_session()
- Fix: ToolCallRecord.status type now includes "running" (was causing TS build error)
- Dockerfile: upgrade npm to latest before install to suppress major-version notice
- npm audit fix: patched minimatch (ReDoS) and rollup (path traversal) — 0 vulnerabilities

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/App.vue

@@ -144,9 +144,10 @@ onUnmounted(() => {
 
 <template>
   <template v-if="authStore.isAuthenticated">
+    <a href="#main-content" class="skip-link">Skip to main content</a>
     <div class="app-shell">
       <AppHeader />
-      <div class="app-content">
+      <div id="main-content" class="app-content">
         <router-view />
       </div>
     </div>
@@ -157,7 +158,7 @@ onUnmounted(() => {
         <div class="shortcuts-panel">
           <div class="shortcuts-header">
             <h3>Keyboard Shortcuts</h3>
-            <button class="shortcuts-close" @click="closeShortcuts">&times;</button>
+            <button class="shortcuts-close" aria-label="Close keyboard shortcuts" @click="closeShortcuts">&times;</button>
           </div>
           <div class="shortcuts-body">
             <div class="shortcuts-section">
@@ -262,6 +263,23 @@ onUnmounted(() => {
 </template>
 
 <style>
+.skip-link {
+  position: absolute;
+  top: -100%;
+  left: 0.5rem;
+  z-index: 9999;
+  padding: 0.4rem 0.75rem;
+  background: var(--color-primary);
+  color: #fff;
+  border-radius: 0 0 4px 4px;
+  font-size: 0.875rem;
+  text-decoration: none;
+  transition: top 0.1s;
+}
+.skip-link:focus {
+  top: 0;
+}
+
 .app-shell {
   display: flex;
   flex-direction: column;