fix(15): convert auth service/tests to async PGlite pattern

The executor agents wrote sync SQLite-style calls (.get(), .all(), .run())
instead of the async Postgres pattern established in Phase 14. Fixed:
- auth.service.ts: use await + destructuring for all DB operations
- auth routes: await listApiKeys
- All auth test files: async createTestDb(), await service calls

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/server/routes/auth.ts

@@ -33,7 +33,7 @@ app.get("/me", async (c) => {
 
 app.get("/keys", requireAuth, async (c) => {
 	const db = c.get("db");
-	const keys = listApiKeys(db);
+	const keys = await listApiKeys(db);
 	return c.json(keys);
 });