Stale Patch Reconciliation

Use when a patch/diff must be compared with, repaired against, or refreshed for a moving checkout — "is this patch still needed", "does upstream already contain it", "what changed since it was written", "reconcile X.diff with HEAD", or "make apply-patches pass again".

This skill has two explicit modes:

• Analysis mode (default): read-only archaeology and a minimal repair plan. Do not edit, reset, stash, clean, update, or restart.
• Repair mode (only when authorized): implement the invariant in an isolated worktree, run focused gates, regenerate the patch from the current baseline and an explicit file allowlist, then apply it to the live checkout only after clean/reverse checks pass. Preserve unrelated dirty work exactly.

Deliverable shape: (1) behavioral invariant, (2) exact gaps/call sites, (3) upstream status, (4) drift cause, (5) minimal repair, (6) focused gate evidence, and (7) artifact/applicator verification. Coordinate writer ownership through shared-worktree-agent-orchestration.

Core sequence

1. Read the full patch first. Paginate the whole diff; note every file touched and the old-file line numbers of each hunk. The hunks are the map for later drift attribution.