fix: brainstorm infinite loop, ghost cursor, embedding ::vector cast, semantic search, billing stats, usage meter accordion

- Fix useBrainstormSocket: stable guestId via useRef, remove setState in cleanup
- Fix GhostCursor: direct DOM manipulation via refs, no useState re-renders
- Fix all SQL embedding queries: add ::vector cast on text columns
- Fix embedding truncation to 15000 chars (under 8192 token limit)
- Fix NoteEmbedding INSERT: remove non-existent updatedAt column
- Fix billing page: show all quota stats in grid instead of single metric
- Fix usage meter: accordion expand/collapse, per-feature detail
- Fix semantic search: rebuild 103 note embeddings, ::vector cast on vectorSearch
- Fix brainstorm expand/manual-idea/create: ::vector cast on embedding SQL

memento-note/app/(main)/home/page.tsx

@@ -0,0 +1,22 @@
+import { getAllNotes } from '@/app/actions/notes'
+import { getAISettings } from '@/app/actions/ai-settings'
+import { HomeClient } from '@/components/home-client'
+
+export default async function HomePage() {
+  const [allNotes, settings] = await Promise.all([
+    getAllNotes(),
+    getAISettings(),
+  ])
+
+  return (
+    <HomeClient
+      initialNotes={allNotes}
+      initialSettings={{
+        showRecentNotes: settings?.showRecentNotes !== false,
+        noteHistory: settings?.noteHistory === true,
+        noteHistoryMode: (settings?.noteHistoryMode ?? 'manual') as 'manual' | 'auto',
+        aiAssistantEnabled: settings?.paragraphRefactor !== false,
+      }}
+    />
+  )
+}