feat(pr-triage): add optional Jev pre-filter wave before parallel review

skills/pr-triage/SKILL.md

@@ -1,13 +1,14 @@
 ---
 name: pr-triage
 description: "Batch-review open PRs in parallel, triage into merge/fix/follow-up buckets, then execute each bucket with per-action human gates on every irreversible operation. Parallel reviews in worktrees compress wall-clock; sequential human-gated merges and diff-only fixes keep blast radius bounded."
-argument-hint: "[--prs <N,N,...>] [--limit <N>] [--repo <owner/repo>] [--auto-merge] [--skip-fix]"
+argument-hint: "[--prs <N,N,...>] [--limit <N>] [--repo <owner/repo>] [--auto-merge] [--skip-fix] [--prefilter | --no-prefilter]"
 category: "Build & ship"
 when-to-use: "When 2+ PRs are open and you want to review, triage, merge, and fix them in a single session. Triggers on 'triage PRs', 'review open PRs', 'batch review', 'clear the PR queue'."
 skills: [review, fix-pr, contract]
-flags: [--auto-merge, --skip-fix, --prs, --limit, --repo]
+flags: [--auto-merge, --skip-fix, --prs, --limit, --repo, --prefilter, --no-prefilter]
 failure_modes:
   - rate_limit_429_on_wide_fanout
+  - jev_prefilter_unavailable_or_path_refused
   - merge_conflict_after_sibling_merge
   - fix_agent_misreads_stale_comment
   - gh_auth_missing
@@ -45,6 +46,8 @@ Parse these from `$ARGUMENTS`:
 | `--repo owner/repo` | (cwd git remote) | Target repository |
 | `--auto-merge` | off | Skip human gate for merge of green PRs (still sequential + CI-gated) |
 | `--skip-fix` | off | Skip Wave 3 fix phase; just triage and merge |
+| `--prefilter` | on for public repos | Force the Wave 0.5 Jev pre-filter on, including for private repos |
+| `--no-prefilter` | off | Skip Wave 0.5; every PR gets a full review |
 
 ## Execution
 
@@ -53,8 +56,8 @@ Parse these from `$ARGUMENTS`:
 1. Verify `gh` CLI is authenticated: `gh auth status`. **Fail closed** if not.
 2. Determine target repo from `--repo` flag or `gh repo view --json nameWithOwner`.
 3. Fetch open PRs:
-   - If `--prs` provided: `gh pr view <N> --json number,title,headRefName,url,author,reviewDecision,statusCheckRollup` for each.
-   - Otherwise: `gh pr list --state open --limit <limit> --json number,title,headRefName,url,author,reviewDecision,statusCheckRollup`.
+   - If `--prs` provided: `gh pr view <N> --json number,title,headRefName,url,author,reviewDecision,statusCheckRollup,isDraft` for each.
+   - Otherwise: `gh pr list --state open --limit <limit> --json number,title,headRefName,url,author,reviewDecision,statusCheckRollup,isDraft`.
 4. If 0 PRs found, report Done with "No open PRs to triage" and stop.
 5. Print the PR manifest table to the operator:
 
@@ -70,12 +73,87 @@ Parse these from `$ARGUMENTS`:
 Proceeding to parallel review wave...
 ```
 
+### Wave 0.5 — Jev pre-filter (inline, optional, fail-open)
+
+Decide how much review each PR gets before paying for it. Jev (TypeSafe AI's
+judgment engine, exposed by the `jev` MCP server) reads each PR's diff
+server-side and answers three narrow questions with calibrated probabilities.
+The diffs never enter this session's context.
+
+**Jev only decides whether a PR is reviewed now, how deeply, and in what order.**
+It never marks a PR GREEN or BLOCKED: those still come only from a `/review`
+verdict, and every merge keeps its gate. Jev judges what a diff looks like, not
+whether it is correct.
+
+**Run only when all of these hold**, otherwise print
+`Pre-filter: off (<reason>)` and go straight to Wave 1 with every PR on the
+Full route:
+
+- `mcp__jev__jev_triage` is in your tool list.
+- `--no-prefilter` is not set.
+- The repo is public (`gh repo view <repo> --json visibility`), or
+  `--prefilter` is set. Private repos are off by default because the pre-filter
+  sends their diffs to TypeSafe's API.
+
+**Steps:**
+
+1. Run `mkdir -p .afk/tmp/pr-triage`, then for each PR write its title, body,
+   changed-file list, and diff to `.afk/tmp/pr-triage/<N>.txt` under the current
+   working directory, using shell redirection only (for example
+   `{ gh pr view <N> --repo <repo> --json title,body,files --jq '.title, .body, (.files[].path)'; gh pr diff <N> --repo <repo>; } > .afk/tmp/pr-triage/<N>.txt`).
+   Do not read these files yourself. They must sit under the working directory,
+   because the Jev server only reads paths below the directory it started in.
+2. Make **one** `mcp__jev__jev_triage` call with one item per PR
+   (`{ "id": "<N>", "path": ".afk/tmp/pr-triage/<N>.txt" }`),
+   `yes_at_or_above: 0.85`, `no_at_or_below: 0.2`, and these questions:
+   - `trivial` (check): "Is every change in this pull request limited to
+     documentation, comments, formatting, lockfiles, or dependency version
+     numbers, with no change to executable logic, configuration behavior, or
+     tests?"
+   - `ready` (check): "Does this pull request look like finished work that is
+     ready for review, with no WIP or draft markers, placeholder code, or TODOs
+     describing unfinished parts of the change?"
+   - `risk` (score), levels lowest first:
+     0. "Touches no security-sensitive or widely shared code."
+     1. "Touches internal code shared by several modules."
+     2. "Touches a public API, persistence or migrations, or concurrency."
+     3. "Touches authentication, credentials, permissions, secret handling, or payments."
+3. Route each PR:
+
+   | Route | Rule | Wave 1 treatment |
+   |-------|------|------------------|
+   | **Light** | `trivial` verdict is yes AND `risk` score < 1.0 | `skill review <pr-url> --light`, model `sonnet` |
+   | **Deferred** | (`isDraft` is true OR `ready` verdict is no) AND the PR was not named in `--prs` | Not reviewed; lands in SKIP with reason `deferred` |
+   | **Full** | Everything else, including every PR whose item errored | Unchanged: `skill review <pr-url>`, model `claude-opus-5-5` |
+
+   If a PR matches both Light and Deferred, Deferred wins.
+4. **Fail open.** If the call errors, the server refuses the paths, or an item
+   returns an `error` (for example a diff over Jev's size limit), that PR goes
+   Full. Never retry by passing the diff as `text`: that pulls it into context,
+   which is what this wave exists to avoid.
+5. Print the routing table under the manifest, then continue to Wave 1 without
+   waiting. Routing is read-only, and the operator can pull any deferred PR back
+   in at Wave 1.5.
+
+```
+## Pre-filter (Jev)
+
+| # | Route | P(trivial) | P(ready) | Risk (0-3) |
+|---|-------|------------|----------|------------|
+| 101 | Light | 0.93 | 0.97 | 0.2 |
+| 102 | Full | 0.04 | 0.91 | 2.6 |
+| 108 | Deferred | 0.01 | 0.12 | 1.1 |
+```
+
 ### Wave 1 — Parallel Review (subagent fan-out)
 
-Dispatch one `agent` call per PR, in parallel:
+Dispatch one `agent` call per PR on the Full or Light route, in parallel.
+Deferred PRs are not dispatched. When Wave 0.5 ran, dispatch in descending
+`risk` order so the riskiest PRs are reviewed first if the session is cut short.
+A PR with no `risk` score (its item errored) counts as highest risk.
 
-- Each call: `skill review <pr-url>`
-- Model: `claude-opus-5-5`
+- Full route: `skill review <pr-url>`, model `claude-opus-5-5`
+- Light route: `skill review <pr-url> --light`, model `sonnet`
 - Cap at 5 concurrent agents. If >5 PRs, run sequential waves of 5 (dispatch the first batch, await all results, then dispatch the next batch).
 - These are read-only reviews — no `isolation: "worktree"` needed.
 
@@ -92,7 +170,7 @@ Classify each PR into exactly one bucket based on the review verdict:
 |--------|----------|
 | **GREEN** | `Decision: MERGE` — zero blocking findings |
 | **BLOCKED** | `Decision: DO NOT MERGE` — has blocking findings. Dispatch `/fix-pr` to address them. |
-| **SKIP** | PR already merged/closed during review, or review failed/timed out |
+| **SKIP** | PR already merged/closed during review, review failed/timed out, or deferred by the Wave 0.5 pre-filter (not reviewed) |
 
 Present the triage table to the operator:
 
@@ -105,6 +183,7 @@ Present the triage table to the operator:
 | 102 | Add dark mode | 🔴 BLOCKED | 2 high | Missing error handling in theme.ts:41, untested edge case |
 | 103 | Bump deps | 🟢 GREEN | 0 | Dep-bump, no issues |
 | 104 | Refactor auth | 🔴 BLOCKED | 1 critical | API contract change needs fix |
+| 108 | WIP: new exporter | ⚪ SKIP | — | Deferred by pre-filter (P(ready) 0.12), not reviewed |
 
 ### Proposed actions:
 - **Merge:** #101, #103 (sequential, CI-gated)
@@ -116,6 +195,7 @@ Awaiting your approval to proceed. Reply with:
 - "merge only" — only merge green PRs
 - "fix only" — only fix blocked PRs
 - "skip <number>" — exclude a specific PR
+- "include <number>" — full-review a deferred PR now, then re-present this table
 - Any custom instruction
 ```
 
@@ -137,6 +217,8 @@ For each GREEN PR, **sequentially** (never parallel):
    and inform operator.
 2. Unless `--auto-merge` is set, confirm with operator:
    `"Merge #<N> '<title>' into <base>? (y/n)"`
+   `--auto-merge` does not cover PRs on the Light route: always confirm those
+   individually, since they were reviewed on a cheaper model.
 3. Merge: `gh pr merge <N> --merge --delete-branch`
    (Use `--merge` not `--squash` unless the PR is single-commit; respect repo's
    merge strategy if detectable from `gh api repos/{owner}/{repo}` settings.)
@@ -224,7 +306,10 @@ Report Done with a structured summary:
 | Fixed + pushed | #102, #104 | ✅ (re-review: GREEN) |
 | Issue (advisory) | #101, #103 | gh#552, gh#553 |
 | Skipped | — | — |
+| Deferred (pre-filter) | #108 | Not reviewed |
 | Still blocked | #107 | Needs upstream API change |
 
-Session closed <N> of <M> PRs.
+Session closed <N> of <M> PRs. Pre-filter: <on: X light, Y deferred | off: reason>.
 ```
+
+If Wave 0.5 ran, delete `.afk/tmp/pr-triage/` before reporting.