RFC: ClusterExtension and ClusterObjectSet status redesign

Proposes improvements to CE and COS status APIs:

- Fix Progressing condition semantics (True/Succeeded → False/Succeeded)
- Add Ready condition to CE for dedicated health signal
- Add status.rollout field with type (Install/Upgrade/Reconfigure) and target bundle
- Add per-phase status to COS for rollout progress visibility
- Rename COS Available → Ready, convert Succeeded condition to succeededAt field
- Stop mirroring COS conditions on CE — translate to CE-native conditions instead
- Update print columns: CE gets Ready/Progressing/Version/Rollout/Target/Age,
  COS gets Revision/Lifecycle/Ready/Progressing/Age
- Remove experimental activeRevisions from CE
- Complete condition/reason audit with reference tables
- 24 scenario examples covering happy paths, CE errors, COS errors, and edge cases

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Per G. da Silva