simplify-diff

name	simplify-diff
description	Use BEFORE opening or proposing any PR — a pre-PR self-review of the diff for reuse, simplification, comment policy, and scope, so review rounds catch design issues instead of mechanical noise. Tier 1, dependency-free.

Simplify the diff before the PR

One pass over git diff <base>...HEAD (plus staged/unstaged changes) by the author, before anyone else sees it. This is a self-check, not the full four-agent /simplify review — it exists so the independent review spends its attention on design, not on lint-shaped findings. Five checks, all mechanical:

1. Reuse. For every new helper or repeated block: grep the package and its neighbours first. If an existing helper does the job, call it. Three near-identical literals are one extraction late.

2. Simplification. Delete dead code, commented-out scaffolding, and state derivable from other state. Collapse copy-paste-with-variation into the one form that varies. Prefer the stdlib call over the hand-rolled loop (dependency ladder rung 1).

3. Comment policy. Every comment must state an external contract, an invariant, or a non-obvious why — never narrate a line. Verify every cited doc id (US-/RFC-/ADR-/AC-) actually exists — a wrong citation propagates by imitation (live escape, 2026-07-16: five sites cited a nonexistent US-0018).

4. Format + gate. gofmt -l on every changed .go file must list nothing; run the repo gate (make check here) before pushing, not after the PR opens.

5. Scope. git diff --name-only lists ONLY files the task names. Anything else is either a revert or a separate task.

Fix what the pass finds, re-run the gate, then open the PR. If a finding is a real design question (wrong altitude, missing seam), do NOT silently fix it in the same diff — surface it to the lead/owner as a note on the PR.