Implement libvirt HA/DR/FT engine with full failover/failback validation

[dhslove]

Summary

This PR introduces the libvirt-based ftctl engine for HA/DR/FT orchestration and carries it through real-environment validation.

Key outcomes:

• HA full failover and full failback implemented and validated
• DR full failover and full failback implemented and validated
• FT file-based full failover and full failback implemented and validated
• FT block-backed full failover and full failback implemented and validated
• Packaging, install, spec, completion, and build workflows aligned for release
• Validation logs and operational docs updated to match final implementation state

Major implementation areas

HA / DR

• Added remote-NBD based protect paths
• Implemented full failback for HA/DR with reverse sync and cutback completion
• Added IPMI fencing support and validation

FT file-based

• Implemented full failback
• Added preflight size validation for prebuilt file-based FT pairs
• Tightened x-colo runtime verification to avoid false-positive colo_running

FT block-backed

• Implemented cold conversion protect flow
• Implemented cold-cutback failback flow
• Added explicit block-backed size mismatch handling

Validation and docs

• Updated failover/failback documentation and runbook
• Updated profile schema to reflect actual supported modes
• Updated test execution log and test-id breakdown
• Reclassified OP-ST-01 under shared-outage handling criteria after final agreement

Validation summary

Validated in real environments:

• HA failover/failback: PASS
• DR failover/failback: PASS
• FT file-based failover/failback: PASS
• FT block-backed failover/failback: PASS
• ST/LV operational scenarios documented with final outcomes

GitHub Actions:

• release build: PASS
• WinPE release build: PASS

Notes

• README.md and INSTALL.md were intentionally left out of this PR as non-blocking follow-up documentation work.
• OP-ST-01 is evaluated as shared storage total outage handling, not host-local path degradation.