Add tests to verify that rig.Manager.AddRig correctly creates witness
and refinery agent beads via initAgentBeads. Also improve mock bd:
- Fix mock bd to handle --no-daemon --allow-stale global flags
- Return valid JSON for create commands with bead ID
- Log create commands for test verification
- Add TestRigAddCreatesAgentBeads integration test
- Add TestAgentBeadIDs unit test for bead ID generation
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>