feat(app): embed indexer in Electron with file-watching service and UI refinements

Extract schema DDL into scripts/schema.sql shared between CLI and app.
  Add an in-process chokidar-based indexer-service that watches ~/.claude/projects
  for JSONL changes, debounces, and triggers background rebuilds via a worker
  thread. Rename Usage view to Activity, flesh out MemoryDetail and SubagentDetail
  views, and refine App.vue layout/routing. The main process now starts/stops the
  indexer lifecycle and notifies renderer windows on index updates.

app/renderer/src/main.js

@@ -17,9 +17,20 @@ const app = createApp(App);
 
 app.use(router);
 
-// Load data before the first render completes
+// Load data on startup
 router.isReady().then(() => {
   loadInitialData();
 });
 
+// Refresh data when window regains focus
+document.addEventListener('visibilitychange', () => {
+  if (document.visibilityState === 'visible') {
+    loadInitialData();
+  }
+});
+
+window.obelisk?.onIndexUpdated?.(() => {
+  loadInitialData();
+});
+
 app.mount('#app');