fix: add missing passwordHash to DB test user factory

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/db/tests/models.test.ts

@@ -23,6 +23,7 @@ async function createUser(overrides: { email?: string; name?: string; role?: 'US
     data: {
       email: overrides.email ?? `test-${Date.now()}@example.com`,
       name: overrides.name ?? 'Test User',
+      passwordHash: '$2b$10$test-hash-placeholder',
       role: overrides.role ?? 'USER',
     },
   });