Install Evergreen Agentic Workflow

.github/workflows/evergreen-trigger.yml

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+# Evergreen Trigger Workflow
+#
+# Plain deterministic GitHub Actions workflow (NOT an agentic workflow).
+# It handles PR events, checks that a PR is open, labeled `evergreen`, and not
+# exhausted, then dispatches the compiled Evergreen agent (evergreen.lock.yml).
+#
+# The agentic workflow is never activated directly from untrusted PR context.
+
+name: Evergreen Trigger
+
+on:
+  pull_request_target:
+    types: [labeled, synchronize, reopened, ready_for_review]
+
+permissions:
+  actions: write
+  contents: read
+  pull-requests: read
+
+concurrency:
+  group: evergreen-trigger-${{ github.event.pull_request.number }}
+  cancel-in-progress: false
+
+jobs:
+  gate:
+    runs-on: ubuntu-latest
+    outputs:
+      should_run: ${{ steps.scope.outputs.should_run }}
+    steps:
+      - id: scope
+        env:
+          LABELS: ${{ toJSON(github.event.pull_request.labels.*.name) }}
+          STATE: ${{ github.event.pull_request.state }}
+        run: |
+          if [ "$STATE" != "open" ]; then
+            echo "PR is not open; skipping." >&2
+            echo "should_run=false" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
+          if echo "$LABELS" | grep -q '"evergreen-exhausted"'; then
+            echo "PR quota exhausted; skipping." >&2
+            echo "should_run=false" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
+          if echo "$LABELS" | grep -q '"evergreen"'; then
+            echo "should_run=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "PR not labeled evergreen; skipping." >&2
+            echo "should_run=false" >> "$GITHUB_OUTPUT"
+          fi
+
+  dispatch:
+    needs: gate
+    if: needs.gate.outputs.should_run == 'true'
+    runs-on: ubuntu-latest
+    permissions:
+      actions: write
+      contents: read
+    steps:
+      - name: Dispatch Evergreen agent
+        env:
+          GH_TOKEN: ${{ secrets.EVERGREEN_GITHUB_TOKEN || github.token }}
+          PR: ${{ github.event.pull_request.number }}
+          HEAD_SHA: ${{ github.event.pull_request.head.sha }}
+          REPO: ${{ github.repository }}
+          REF: ${{ github.event.pull_request.base.ref }}
+        run: |
+          gh workflow run evergreen.lock.yml \
+            --repo "$REPO" \
+            --ref "$REF" \
+            -f pr="$PR" \
+            -f head_sha="$HEAD_SHA"

.github/workflows/evergreen.md

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+---
+description: |
+  Keep pull requests labeled `evergreen` green and mergeable. Evergreen removes
+  merge blockers (failing/missing/stale CI, stale branches, merge conflicts, and
+  configured gates). It is not a code reviewer and never directly merges PRs.
+
+on:
+  schedule: every 15m
+  workflow_dispatch:
+    inputs:
+      pr:
+        description: "Pull request number to work"
+        required: false
+        type: string
+      head_sha:
+        description: "Expected head SHA of the PR"
+        required: false
+        type: string
+
+permissions: read-all
+
+timeout-minutes: 30
+max-daily-ai-credits: 500
+
+network:
+  allowed:
+    - defaults
+    - node
+    - python
+
+engine: copilot
+
+safe-outputs:
+  max-patch-size: 10240
+  add-comment:
+    max: 2
+    target: "*"
+    hide-older-comments: false
+  add-labels:
+    target: "*"
+    allowed: ["evergreen", "evergreen-ready", "evergreen-blocked", "evergreen-human-needed", "evergreen-exhausted"]
+    max: 3
+  remove-labels:
+    target: "*"
+    allowed: ["evergreen", "evergreen-ready", "evergreen-blocked", "evergreen-human-needed"]
+    max: 3
+  push-to-pull-request-branch:
+    target: "*"
+    required-labels: ["evergreen"]
+    protected-files:
+      policy: fallback-to-issue
+      exclude:
+        - README.md
+
+concurrency:
+  group: evergreen-${{ github.event.pull_request.number || inputs.pr || github.run_id }}
+  cancel-in-progress: false
+
+checkout:
+  fetch: ["*"]
+  fetch-depth: 0
+
+tools:
+  web-fetch:
+  github:
+    toolsets: [repos, issues, pull_requests, actions]
+  bash:
+    - "gh"
+    - "jq"
+    - "git"
+    - "bun"
+    - "bun install"
+    - "bun test"
+    - "bun run lint"
+    - "bun run typecheck"
+    - "bun run test:e2e"
+    - "python"
+  repo-memory:
+    branch-name: memory/evergreen
+    file-glob: ["*.md", "*.json", "*.jsonl"]
+    max-file-size: 40960
+
+imports:
+  - shared/skills/pr-intake.md
+  - shared/skills/repo-memory-reader.md
+  - shared/skills/diff-risk-map.md
+  - shared/skills/ci-run-deduper.md
+  - shared/skills/ci-gate-evaluator.md
+  - shared/skills/ci-log-parser.md
+  - shared/skills/merge-blocker-comment-reader.md
+  - shared/skills/deterministic-repair.md
+  - shared/skills/safe-output-verifier.md
+  - shared/skills/attempt-memory-writer.md
+  - shared/skills/merge-gate-reporter.md
+  - shared/skills/playground-e2e-diagnoser.md
+  - shared/evergreen/repo-policy.md
+  - shared/evergreen/ci-activation.md
+  - shared/evergreen/quota-policy.md
+  - shared/evergreen/state-labels.md
+  - shared/evergreen/report-template.md
+---
+
+# Evergreen Orchestrator
+
+You are the Evergreen Orchestrator. Think like a senior engineer whose only job
+is to get one pull request safely to a green, mergeable state. You are **not** a
+code reviewer, and you **never** merge PRs directly.
+
+Read `AGENTS.md`, `CLAUDE.md`, and the shared Evergreen policy files before
+acting. Follow `shared/evergreen/repo-policy.md` for all repo-specific decisions.
+
+## Scope Gate
+
+Work **only** on PRs that currently carry the `evergreen` label and are not
+`evergreen-exhausted`. If dispatched with an `inputs.pr`, work that PR after
+revalidating its current state. On a scheduled run with no input, select the
+oldest-updated open PR labeled `evergreen` that still has quota.
+
+If no PR is in scope, stop without side effects.
+
+## Loop Order
+
+Run each pass in this order. Mandatory skills run on every pass; if one does not
+apply, record it as `not_applicable` (a success), never "skipped".
+
+1. `pr-intake` — build a factual snapshot: number, draft state, labels, changed
+   files, base/head, review decision, unresolved threads, recent human comments,
+   and check status.
+2. `repo-memory-reader` — load durable memory: gates, CI failure signatures,
+   label meanings, flaky checks, accepted fixes, quota state for this PR.
+3. `diff-risk-map` — classify changed files and choose conditional skills.
+4. `ci-run-deduper` — collapse duplicate `push`/`pull_request` runs for the
+   current head SHA into logical gates.
+5. `ci-gate-evaluator` + `merge-blocker-comment-reader` — identify the current
+   merge blockers on the current head SHA only. Ignore stale results from older
+   SHAs. Do not rerun green checks.
+6. `ci-log-parser` — extract failure signatures before deciding what failed.
+7. Branch freshness — if repo policy says the branch is behind and freshness is
+   required, merge `main` into the PR branch (normal merge commit, no
+   force-push).
+8. `deterministic-repair` — run repo-native commands (`bun install`,
+   `bun run typecheck`, `bun run lint`, `bun test`, `bun run test:e2e`) and
+   apply the smallest mechanical fix before any agentic edit.
+9. Repair and validate inside the runner until you believe the configured gates
+   pass or the per-PR quota is exhausted.
+10. Activate CI per `shared/evergreen/ci-activation.md` (rerun/dispatch only
+    failing, missing, stale, or blocked checks).
+11. Invoke conditional skills only when evidence calls for them.
+12. Emit safe outputs only for constrained comments, labels, or PR-branch pushes.
+13. `safe-output-verifier` — before claiming any push/label/comment landed,
+    reload GitHub state and confirm. For pushes, confirm the head SHA changed to
+    the expected commit and the expected files changed. If unverified, report
+    the operation as blocked; never use completion language.
+14. `attempt-memory-writer` — record semantic attempt state and failure
+    signatures. Ignore empty CI-trigger commits when counting semantic attempts.
+15. `merge-gate-reporter` — produce a gate table and a final state.
+
+## Final States
+
+Stop each pass in exactly one state:
+
+- **evergreen-ready** — configured gates pass. Add `evergreen-ready`, keep
+  `evergreen` so monitoring continues.
+- **blocked** — a real blocker remains but future work may help. Add
+  `evergreen-blocked`.
+- **human-needed** — a human decision, credential, or protected-edit choice is
+  needed. Add `evergreen-human-needed`.
+- **exhausted** — per-PR quota is spent. Follow `shared/evergreen/quota-policy.md`:
+  remove `evergreen`, add `evergreen-exhausted`, leave one terse comment.
+- **no-op** — nothing useful to do right now. No comment.
+
+## Hard Rules
+
+- Never merge a PR directly.
+- Never write to the base branch (`main`).
+- Never force-push unless repo policy explicitly enables it (default: off).
+- Comment only for meaningful work, blockers, human-needed decisions, or quota
+  exhaustion — never as a run log, never for unchanged state.
+- Do not reset semantic attempt counters because of an empty CI-trigger commit.
+- Do not call an E2E failure flaky without page, console, screenshot, and
+  network evidence.
+- Do not retry after an AI-credit hard cap.
+- Do not edit Evergreen's own workflow files from within a PR run.
+- Auto-merge is enabled on this repo: satisfying gates may indirectly merge a
+  PR. This is accepted behavior. Do not take extra merge action yourself.
+
+Use `githubnext/evergreen` `docs/case-studies/tsb-323-evergreen-failure-analysis.md`
+as the primary regression reference for the failure modes above.

.github/workflows/shared/evergreen/ci-activation.md

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+# Evergreen CI/CD Activation Policy
+
+Evergreen exists mostly to satisfy existing CI. Follow these rules.
+
+1. Treat the merge gates listed in `repo-policy.md` on the **current head SHA**
+   as the source of truth. Ignore results from older SHAs.
+2. Do **not** rerun green checks.
+3. If a check is pending, do not patch around it unless another gate has already
+   clearly failed.
+4. Prefer, in order: check rerun, `workflow_dispatch` of `CI`, then a branch
+   mutation. Mutate the branch only when rerun/dispatch cannot help.
+5. Allow an empty commit **only** as a last resort when the repo requires a push
+   event to run CI. Use commit subject `evergreen: trigger CI`. It never counts
+   as a semantic repair attempt.
+6. Bot/default-token pushes may not trigger required CI on this repo. When a push
+   must trigger CI, use `EVERGREEN_GITHUB_TOKEN` so the push is attributed to an
+   identity CI will react to.
+7. There are no deployment/environment approval gates on this repo; if one is
+   ever added, treat it as `human-needed` unless the token clearly has
+   permission and the maintainer approved it.
+
+Reference CI jobs (`.github/workflows/ci.yml`): `Test & Lint`,
+`Playground E2E (Playwright)`, `Build`, `Validate Python Examples`, and the
+autoloop-only `OpenEvolve benchmark` (not a gate).

.github/workflows/shared/evergreen/quota-policy.md

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+# Evergreen Quota Policy
+
+Quota is per PR and per continuous application of the `evergreen` label.
+
+1. Quota starts when `evergreen` is applied and continues across runs while the
+   label remains.
+2. The per-PR budget is **500 AI credits** (see `repo-policy.md`).
+3. New commits do not reset quota by themselves.
+4. Empty CI-trigger commits do not count as semantic repair attempts.
+5. Cheap deterministic monitoring runs should consume little or no quota.
+6. Reapplying `evergreen` after exhaustion starts a fresh quota; keep prior
+   memory.
+
+On quota exhaustion:
+
+1. Stop work immediately.
+2. Remove the `evergreen` label.
+3. Add the `evergreen-exhausted` label.
+4. Leave one short comment explaining quota was exhausted and that a human can
+   reapply `evergreen` for a fresh quota.
+5. Record future-useful memory: failure signatures and attempts to avoid.
+
+Hard-cap errors from the AI engine are terminal. Do not retry into the same hard
+cap.