Always remove unrelated diff churn before merging

Keep the working tree, staging area, commits, and final diff strictly limited to the approved request. Treat unrelated formatter-, whitespace-, newline-, quote-, lockfile-, generated-, or baseline-only changes as merge blockers: inspect their provenance, preserve pre-existing unrelated changes exactly, exclude them from staging, and revert incidental churn. Use non-destructive checks when broad commands could rewrite files. Before finalizing, inspect the exact modified-file list and diff; retain only intentional implementation, documentation, and focused test changes, with no unintended artifacts.