EXECUTION MODE ENABLED

Phase 2 execution switch:
- replacement_phase2_rebuild_and_rejoin=true

Phase 3 execution switch:
- replacement_phase3_identity_cutover=false

Phase 4 execution switch:
- replacement_phase4_validate_cutover=false

Manual steps still required around identity cutover:
1. If phase 2 enabled, rebuild and rejoin replacement swarm nodes on pve04.
2. If phase 3 enabled, update inventory/group_vars source-of-truth with rollback snapshots.
3. If phase 4 enabled, validate swarm quorum and optional service endpoints.
4. Move network identity 10.0.0.201 to replacement physical host.
5. If stable and approved, power off old host.
