Retarget hotfixes with both tree scope and commit ancestry in view

When retargeting a fix branch from staging to a production branch, verify both the final file diff and the commit ancestry. Reverting a staging merge can produce a small production diff while retaining staging feature commits as ancestors. A later staging-to-production merge can then treat those commits as already integrated, even though their changes were reversed. A clean diff alone is therefore insufficient evidence of a safely isolated hotfix.

Applicability and limits: this matters when the fix branch has merged a target branch containing unreleased work. For an owned branch with a verified pre-merge fix state, restore that clean history using the approved repository workflow; preserve a backup reference and protect any history update with an exact remote lease. Do not rewrite shared branches or remove others' commits without authorization. An intentional merge revert can still be correct when its future reintroduction plan is explicit.