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>

tests/routes/auth.test.ts

@@ -20,8 +20,8 @@ mock.module("../../src/server/services/oauth.service", () => ({
 // Import routes AFTER mocks
 const { authRoutes } = await import("../../src/server/routes/auth.ts");
 
-function createTestApp() {
-	const db = createTestDb();
+async function createTestApp() {
+	const db = await createTestDb();
 	const app = new Hono<{ Variables: { db?: any } }>();
 
 	app.use("*", async (c, next) => {
@@ -35,10 +35,10 @@ function createTestApp() {
 
 describe("Auth Routes", () => {
 	let app: Hono;
-	let db: ReturnType<typeof createTestDb>;
+	let db: Awaited<ReturnType<typeof createTestDb>>;
 
-	beforeEach(() => {
-		const testApp = createTestApp();
+	beforeEach(async () => {
+		const testApp = await createTestApp();
 		app = testApp.app;
 		db = testApp.db;
 		mockGetAuth.mockReset();