feat: pr-gate, the estate merge gate on GitHub

.github/workflows/pr-gate-test.yml

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+name: pr-gate tests
+
+on:
+  pull_request:
+    paths: ['pr-gate/**', '.github/workflows/pr-gate*.yml']
+  push:
+    branches: [main]
+    paths: ['pr-gate/**', '.github/workflows/pr-gate*.yml']
+
+concurrency:
+  group: pr-gate-test-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+      - run: node --test pr-gate/decide.test.mjs

.github/workflows/pr-gate.yml

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+name: pr-gate
+
+# Reusable merge gate. Callers install pr-gate/caller.yml and pin this file to a commit SHA.
+# It reads the PR through the API and never checks out or runs the PR's code, which is what makes
+# running it from pull_request_target safe.
+on:
+  workflow_call:
+    inputs:
+      pr-number:
+        description: PR to judge, as a string. Anything that is not a plain number is a no-op.
+        required: true
+        type: string
+      merge:
+        description: Squash-merge when every condition passes. False = report only.
+        required: false
+        type: boolean
+        default: false
+      gate-ref:
+        description: Commit of Starlight-Intelligence/.github to load the gate from. Pin it to the same SHA as the uses line.
+        required: false
+        type: string
+        default: main
+      required-checks:
+        description: Comma-separated check run names that must pass on the head commit, e.g. "test, build".
+        required: true
+        type: string
+      wait-minutes:
+        description: How long to wait for running CI when it is the only thing outstanding.
+        required: false
+        type: number
+        default: 8
+
+jobs:
+  decide:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    permissions:
+      contents: write
+      pull-requests: write
+      issues: write
+      checks: read
+    steps:
+      - name: Load the gate
+        uses: actions/checkout@v4
+        with:
+          repository: Starlight-Intelligence/.github
+          ref: ${{ inputs.gate-ref }}
+          path: .pr-gate
+          persist-credentials: false
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+
+      - name: Decide
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+          PR_NUMBER: ${{ inputs.pr-number }}
+          PR_GATE_MERGE: ${{ inputs.merge }}
+          PR_GATE_WAIT_MINUTES: ${{ inputs.wait-minutes }}
+          PR_GATE_REQUIRED_CHECKS: ${{ inputs.required-checks }}
+        run: node .pr-gate/pr-gate/run.mjs

pr-gate/CODE-REVIEW-RULES.md

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+## Code Review Rules
+
+Codex reviews here as the second provider: most PRs in this repo are written by Claude. Flag as P0 or P1:
+
+- A claim in code, copy or docs with no evidence behind it: invented metrics, counts, testimonials, "verified" or "trusted by" without a source.
+- Anything that fakes or bypasses CI: posting commit statuses by hand, skipping tests, `--admin`, `--no-verify`, tests rewritten to match broken behavior, graders a do-nothing run can pass.
+- Secrets, tokens or keys in code, logs or tests; `.env` values committed.
+- Money, auth, env or dependency changes, and new or deleted public pages, without a linked ruling from Frank.
+- A checkout, buy button or install command for something that is not purchasable or published yet. Unlaunched products use the waitlist.
+- Unbounded loops, retries or agent fan-out with no cap.
+- On web surfaces: `100vh` in shells, hover styles outside `(hover: hover) and (pointer: fine)`, inputs under 16px, zoom disabled, motion with no `prefers-reduced-motion` path.
+
+Do not flag style preferences already enforced by the linter.

pr-gate/README.md

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+# pr-gate
+
+The estate merge gate, running on GitHub instead of a laptop. On the PR's current head commit it passes only when:
+
+- A review from a GitHub bot identity of a different harness than the author exists for that commit: `chatgpt-codex-connector[bot]` (Codex) or `claude[bot]` (Claude). The author is read from the branch prefix, because every harness pushes as the same GitHub account.
+- That review is an approval, or a review whose body says it found no major issues. Dismissed and pending reviews are ignored. A bot review mentioning P0 or P1 blocks, and so does a bot comment that names a P0 or P1 against the head. Bot comments never sign off, because they carry no commit id.
+- A renamed file is judged on both its old and new path.
+- Every check named in the repo's `required-checks` has a latest attempt that succeeded, no other check failed, and nothing is still running. Commit statuses never count: anything holding a token can post one, which is how 20 PRs merged on 2026-10-19 with no check having run.
+- All review threads are resolved (every page read; an unreadable answer blocks) and the full list of changed files was read.
+- It is not a draft, carries no `hold` / `do-not-merge` / `blocked` / `wip` label, and its body links the intent it serves (an issue, board item or ruling).
+- It touches none of Frank's paths: workflows, env files, dependencies, money, auth and middleware, `vercel.json`, or a new or deleted public page. No label overrides this. Labels prove nothing about who applied them on a shared account, so Frank merges those himself.
+
+In merge mode it decides again from fresh facts just before merging and merges with a head-SHA guard.
+
+## What does not count
+
+Typed lines (`starlight-signoff: ...` from the estate `tools/pr-gate.mjs`, `Checker: claude-cloud · head <sha> · verdict PASS`) are shown as advisory but never pass the gate: the author can type them. The estate `pr-gate.mjs` still honours them for a merge a human runs.
+
+So today, Claude-authored PRs pass once Codex reviews them. Codex- and Gemini-authored PRs pass only after a review from the Claude GitHub bot, or a human-run merge.
+
+Branch prefixes: `agent/claude/`, `claude/`, `ccr-` and `factory/` (Foreman, whose implementer is an Anthropic model) are Claude; `codex/`, `agent/codex/`, `agent/gpt*` are Codex; `agent/antigravity/`, `agent/gemini/`, Jules and `sentinel-` branches are Gemini.
+
+## Install in a repo
+
+1. Copy `caller.yml` to `.github/workflows/pr-gate.yml` and `poke.yml` to `.github/workflows/pr-gate-poke.yml`. Replace both `GATE_SHA` with a commit of this repo, list the repo's CI workflow names under `workflow_run`, and its check names in `required-checks`.
+2. Turn on Codex code review and automatic reviews for the repo in Codex settings.
+3. Add the section in `CODE-REVIEW-RULES.md` to the repo's `AGENTS.md`.
+4. Start with `merge: false` (report only). Flip to `merge: true` where autonomous landing is ruled.
+
+Every trigger runs the caller from the default branch. Review events go through `pr-gate-poke`, which holds no permissions, and come back as `workflow_run`.
+
+## Known limits
+
+- Without branch protection nothing stops someone merging around the gate; the private repos on the free plan cannot have it. The gate is the merge path agents are told to use, not a lock.
+- Between the final decision and the merge call a few milliseconds remain in which a review could be dismissed. Only a required status check under branch protection closes that.
+- A same-repo PR's own workflows run with the repo token. The gate refuses to merge any PR that edits workflows, but cannot stop such a PR from posting a same-named check on itself.
+- A squash merge made with the workflow token does not trigger push workflows on the base branch. Vercel's git integration still deploys.
+
+Tests: `node --test pr-gate/decide.test.mjs`.

pr-gate/caller.yml

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+# Copy to .github/workflows/pr-gate.yml in a product repo, with poke.yml beside it.
+# Replace GATE_SHA (both places) with a commit of Starlight-Intelligence/.github, list the repo's CI
+# workflow names under workflow_run and its check names in required-checks, and set merge to true
+# only where autonomous landing is ruled.
+#
+# Every trigger here runs this file from the default branch, never from the PR, so a PR cannot
+# rewrite the gate it is judged by. Reviews arrive through pr-gate-poke (no permissions) and come
+# back here as workflow_run.
+name: pr-gate
+
+on:
+  pull_request_target:
+    types: [opened, synchronize, reopened, ready_for_review, labeled, unlabeled, edited]
+  issue_comment:
+    types: [created]
+  workflow_run:
+    workflows: [pr-gate-poke, CI]
+    types: [completed]
+
+permissions:
+  contents: write
+  pull-requests: write
+  issues: write
+  checks: read
+
+concurrency:
+  group: pr-gate-${{ github.event.pull_request.number || github.event.issue.number || github.event.workflow_run.pull_requests[0].number || github.event.workflow_run.display_title }}
+  cancel-in-progress: true
+
+jobs:
+  pr-gate:
+    # Comments re-run the gate only for a result from an allowlisted reviewer bot, or an exact
+    # `/gate` from an owner or org member. A comment can only trigger a re-read, never a sign-off.
+    if: >-
+      (github.event_name == 'pull_request_target') ||
+      (github.event_name == 'workflow_run') ||
+      (github.event_name == 'issue_comment' && github.event.issue.pull_request && (
+        contains(fromJSON('["chatgpt-codex-connector[bot]","claude[bot]"]'), github.event.comment.user.login) ||
+        (github.event.comment.body == '/gate' && contains(fromJSON('["OWNER","MEMBER"]'), github.event.comment.author_association))))
+    uses: Starlight-Intelligence/.github/.github/workflows/pr-gate.yml@GATE_SHA
+    with:
+      # Reusable inputs are typed; the number is passed as a string. A relayed review with no PR
+      # attached falls back to the poke run title, which is the PR number.
+      pr-number: ${{ format('{0}', github.event.pull_request.number || github.event.issue.number || github.event.workflow_run.pull_requests[0].number || github.event.workflow_run.display_title) }}
+      required-checks: test
+      merge: false
+      gate-ref: GATE_SHA