- Test 1-2: PKCE generation (verifier/challenge format, auth URL params)
- Test 3: token exchange posts correct body to Google token endpoint
- Test 4-5: storeTokens create and rotate paths
- Test 6: authorize returns {url, stateId} with no companyId in pendingPkce
- Test 7: callback exchanges code and redirects with google_oauth=success
- Test 8: callback with invalid state returns 400
- Test 9: full authorize->callback->claim flow stores tokens by companyId
- Test 10: claim with missing stateId returns 404
- Test 11: api-keys/store upserts via secretService
