- OAuth: add userId to oauth_codes schema and migration, derive userId
from stored auth code/token record instead of passing separately
- Auth middleware tests: destructure {db, userId} from createTestDb,
pass userId to createApiKey, fix error message assertion
- MCP tests: add missing await on getCollectionSummary and
createSecondTestUser calls
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>