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/services/auth.service.test.ts

@@ -8,10 +8,10 @@ import {
 import { createTestDb } from "../helpers/db.ts";
 
 describe("Auth Service", () => {
-	let db: ReturnType<typeof createTestDb>;
+	let db: Awaited<ReturnType<typeof createTestDb>>;
 
-	beforeEach(() => {
-		db = createTestDb();
+	beforeEach(async () => {
+		db = await createTestDb();
 	});
 
 	describe("API Key Management", () => {
@@ -41,7 +41,7 @@ describe("Auth Service", () => {
 
 		it("deletes key so it is no longer valid", async () => {
 			const result = await createApiKey(db, "test-key");
-			deleteApiKey(db, result.id);
+			await deleteApiKey(db, result.id);
 
 			const isValid = await verifyApiKey(db, result.rawKey);
 			expect(isValid).toBe(false);
@@ -51,7 +51,7 @@ describe("Auth Service", () => {
 			await createApiKey(db, "key-one");
 			await createApiKey(db, "key-two");
 
-			const keys = listApiKeys(db);
+			const keys = await listApiKeys(db);
 			expect(keys).toHaveLength(2);
 			expect(keys[0].name).toBe("key-one");
 			expect(keys[1].name).toBe("key-two");