docs: add beta release and rollback guide - #52

❌ PatchGate Snapshot Rejected

Event PR Head SHA: d0316e380caea6c87227df8a7b307829afef98e0
Diagnostic: GITHUB_PROVENANCE_AMBIGUOUS
Message: Native ruleset or branch-protection visibility is incomplete; the current evaluator cannot safely treat unknown native controls as absent.
Remediation: Grant the documented native-control read permissions and rerun, or keep the native-control snapshot rejected.