feat(db): migrate from lowdb to SQLite with repos pattern

- Add modular DB layer (adapters, migrations, repos, helpers)
- Replace localDb/usageDb/requestDetailsDb monoliths with repos
- Add Tailscale tunnel integration & status check API
- Add /api/cli-tools/all-statuses aggregated endpoint
- Add settingsStore (Zustand) and mitm/dbReader
- Add DB unit tests (benchmark, concurrent, migration, vs-lowdb)

src/lib/initCloudSync.js

@@ -20,9 +20,12 @@ export async function ensureAppInitialized() {
   return g.inProgress;
 }
 
-// Auto-initialize at runtime only, not during next build
+// Auto-initialize at runtime only, not during next build.
+// Defer to next tick so HTTP server can accept connections before heavy init runs.
 if (process.env.NEXT_PHASE !== "phase-production-build") {
-  ensureAppInitialized().catch(console.log);
+  setImmediate(() => {
+    ensureAppInitialized().catch(console.log);
+  });
 }
 
 export default ensureAppInitialized;