- Add 'pending' to grantStatusEnum (pending → active → revoked/expired)
- Update federationGrants default status to 'pending'
- Add migration 0009_federation_grant_pending.sql
- GrantsService: createGrant, getGrant, listGrants, activateGrant, revokeGrant, expireGrant
- Invalid transitions throw ConflictException; missing grants throw NotFoundException
- CreateGrantDto validates scope via parseFederationScope before insert
- Full unit test coverage for all status transitions and edge cases
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>