pr-diff-verification

# PR Diff Verification ## When to invoke Before: - `git push` of a feature branch (especially after subagent return) - `gh pr create` - `gh pr merge` (final sanity) - Force-push (`--force-with-lease`) of a rebased branch Skip when: pushing a single trivial commit you authored line-by-line in the current session and didn't amend. ## The pattern (3-step verify) ### Step 1 — read the commit message claims For the HEAD commit (or all commits on the branch since base), extract concrete claims: - "modifies X" → look for X in the diff - "adds Y" → look for `create mode 100644 Y` in the `--summary` output - "deletes Z" → look for `delete mode 100644 Z` in the `--summary` output - "renames A → B" → look for `rename dir/{A => B} (NN%)` in the `--summary` output - "fixes N+M lines" → diff total should be in that ballpark ### Step 2 — compare against actual diff ```bash git show --stat --summary HEAD # for single commit git diff --stat --summary origin/main..HEAD # for branch cumulative git log --oneline origin/main..HEAD # for commit count ``` Plain `--stat` only prints `path | N +-` per file; the `create mode` / `delete mode` / `rename A => B (NN%)` lines only appear with `--summary` added. For each concrete claim, grep the stat output. If the claim mentions a path that doesn't appear in the stat, that's a discrepancy — investigate before push. ### Step 3 — surface discrepancies If found: - Did `git commit --amend` or rebase squash the...