fix-pr

## Sub-agent contract /contract `fix-pr` turns "review feedback / red CI on PR N" into a pushed fix commit with test evidence, using worktree isolation so the operator's working tree is never disturbed. The pipeline has three stages: **harvest** (collect feedback from all GitHub stores), **triage** (parallel read-only probes validate each issue independently), and **fix** (a single write agent applies pre-validated proposals). The parallel triage wave eliminates false-positive spec items and pre-computes fix proposals before any write begins, reducing cycling. **Skip when:** the fix is a one-line suggestion the operator pointed at directly (apply inline); the PR is already green with all threads resolved (report and stop); or the work is local-only and unpushed (use `/ship`). --- ### Phase 0 — Input gate & preflight (inline, fail closed) Parse `$ARGUMENTS`: - **`pr`** — PR number or URL (required). If absent, stop: "fix-pr requires a PR number or URL." - **`repo`** — repo path from `--repo`; default: current working directory's git root. - **`no_push`** — from `--no-push`: produce the fix in a kept worktree + diff summary, no remote mutation. - **`re_review`** — from `--re-review`: after pushing, re-trigger `/review` (top-level only — see Phase 6 guard). Preflight (all inline bash; any failure → **Blocked**, do not improvise): 1. `gh auth status` — must be authenticated. Fail closed if not. 2. `gh pr view <pr> --json state,headRefName,headRepositoryOwner,isCrossReposito...