# R720 agent-team — split-job CI apply/verify workflow (design §3.3.2, §7.1 P3).
#
# DEPLOY-GATED PRE-DEPLOYMENT SCAFFOLDING. This file is authored as IaC only.
# It is NOT enabled, NOT provisioned, and NOT wired to any live org repo. Per
# the design (§3.3.2, §7.1 P3) it must clear BOTH `/sh-security-review` AND the
# mandatory GPT-4.1 cross-review before it is deployed (it is IaC/IAM +
# untrusted-input handling). Until then it lives here as a reviewable artifact.
#
# Deployment target (later, after the gates): promote into
# Sea-Haven-Industries/.github as a reusable workflow (engineering-handbook
# cicd.md) and have the Option-B OIDC apply path call it. The filename stays
# kebab-case per the handbook.
#
# ─────────────────────────────────────────────────────────────────────────────
# TRUST BOUNDARY (design §3.3.2). The builder agents are semi-trusted: an LLM
# that read repo content can be wrong or prompt-injected, so the candidate diff
# is UNTRUSTED CODE. The five boundaries this workflow implements:
#
#   1. Split CI. The job that checks out + executes the patch (`build-test`)
#      runs credential-less (`permissions: contents: read`, no secrets, no
#      OIDC, no write token, egress-restricted). Every privileged action runs
#      in a SEPARATE job (`gate-and-pr`) that NEVER checks out or runs
#      patch-controlled code; it consumes the build/test report as DATA only.
#      This is NOT `pull_request_target` with a head-ref checkout (pwn request).
#   2. Trust-control-surface denylist. `guard` hard-fails (CI-side, not only the
#      box) any diff touching `.github/workflows/**`, IAM/policy IaC, branch
#      protection / CODEOWNERS / Dependabot, or files outside the declared task
#      scope. It canonicalizes paths, resolves symlinks, and rejects renames
#      into denied paths — a path match cannot be bypassed by indirection.
#   3. Diff integrity, box → CI. CI re-hashes the candidate diff and verifies it
#      equals the ledger-recorded hash BEFORE applying. Tamper/substitution
#      fails the hash check.
#   4. Pure-code pass/fail gate. A deterministic gate reads the authenticated
#      build/test conclusion keyed to (run id + diff hash). It never trusts a
#      success/failure file the patch could have written. The verifier AGENT
#      only reads failures to propose a fix; it cannot declare success.
#   5. Branch protection. The draft PR targets a protected branch; the
#      locked-down checks are required; merge needs them green + the
#      security-review + the Claude Code App review + human approval. The agent
#      NEVER auto-merges (D2).
#
# All third-party actions are SHA-pinned (handbook Pinning Principle, §3.3.2).
# ─────────────────────────────────────────────────────────────────────────────

name: agent-team-apply-verify

# Manual / API trigger only. The Option-B OIDC apply path (a trusted, separate
# workflow that owns the write token) invokes this with the candidate-diff
# artifact + the ledger-recorded hash + the declared scope. There is NO
# pull_request / pull_request_target trigger: the patch must never run in a
# context that carries write or secret scope (boundary 1).
on:
  workflow_dispatch:
    inputs:
      task_id:
        description: "Pipeline task thread_id (for provenance/audit)."
        required: true
        type: string
      diff_artifact_name:
        description: "Name of the uploaded candidate-diff artifact."
        required: true
        type: string
      expected_diff_hash:
        description: "Ledger-recorded sha256 of the candidate diff (boundary 3)."
        required: true
        type: string
      declared_scope:
        description: >-
          Newline-separated list of glob paths the task is allowed to touch
          (boundary 2). A diff that changes anything outside this set fails.
        required: true
        type: string

# Workflow-level default: least privilege. Every job re-declares its own
# `permissions:` so the grant is explicit per job and the untrusted job can be
# audited at a glance.
permissions: {}

# One in-flight apply/verify per task; a re-dispatch cancels the stale run so a
# superseded diff cannot race a newer one.
concurrency:
  group: agent-team-apply-verify-${{ inputs.task_id }}
  cancel-in-progress: true

jobs:
  # ───────────────────────────────────────────────────────────────────────────
  # JOB 1 — guard (boundaries 2 + 3). Credential-less. Validates the candidate
  # diff WITHOUT applying or executing it: re-hashes it (integrity) and runs the
  # trust-control-surface denylist + declared-scope check. This job reads the
  # diff as DATA only — it never `git apply`s it, so even a hostile diff cannot
  # run code here. A failure is terminal: the diff is rejected and ALARM-worthy.
  # ───────────────────────────────────────────────────────────────────────────
  guard:
    runs-on: ubuntu-latest
    timeout-minutes: 5
    permissions:
      contents: read
    outputs:
      diff_hash: ${{ steps.verify.outputs.diff_hash }}
    steps:
      - name: Harden runner (egress audit; no secrets present anyway)
        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
        with:
          egress-policy: block
          # Only what fetching the artifact + GitHub API needs. The job holds
          # no secrets, so a successful exfil yields nothing of value (§3.3.2),
          # but we deny egress as defense-in-depth.
          allowed-endpoints: >
            github.com:443
            api.github.com:443
            objects.githubusercontent.com:443
            *.actions.githubusercontent.com:443

      - name: Download candidate diff (data only; not applied)
        uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4.1.8
        with:
          name: ${{ inputs.diff_artifact_name }}
          path: ./_incoming

      - name: Verify diff integrity + trust-control denylist + scope
        id: verify
        env:
          EXPECTED_DIFF_HASH: ${{ inputs.expected_diff_hash }}
          DECLARED_SCOPE: ${{ inputs.declared_scope }}
          DIFF_PATH: ./_incoming/candidate.diff
        run: |
          set -euo pipefail
          # Self-contained, stdlib-only, type-hinted gate program embedded
          # inline so this workflow has NO external script dependency. It is
          # patch-independent: it parses the unified diff as TEXT and never
          # executes it. It re-hashes the diff (boundary 3) and enforces the
          # trust-control-surface denylist + declared scope (boundary 2),
          # canonicalizing paths and rejecting renames into denied paths.
          python3 - <<'PY'
          from __future__ import annotations

          import hashlib
          import os
          import posixpath
          import re
          import sys

          # --- Boundary 2: the trust-control surface. Touching ANY of these is
          # an auto-reject; such a diff is escalated to mandatory human + GPT
          # cross-review, never auto-built (these are the mandatory-cross-review
          # surface regardless). Matched against canonicalized POSIX paths. ---
          DENY_GLOBS: tuple[str, ...] = (
              ".github/workflows/**",
              ".github/actions/**",
              "**/CODEOWNERS",
              "CODEOWNERS",
              ".github/dependabot.yml",
              ".github/dependabot.yaml",
              ".github/settings.yml",
              # IAM / policy / permission IaC (CDK / SAM / Terraform).
              "**/template.yaml",
              "**/template.yml",
              "**/*.tf",
              "**/cdk.json",
              "**/*-stack.ts",
              "**/*_stack.py",
              "**/policy*.json",
              "**/*iam*",
              "**/*.pem",
              "**/*.key",
          )

          def canonical(path: str) -> str:
              """Canonicalize a diff path to a normalized, anchored POSIX path.

              Strips git's a//b/ prefixes, collapses ``.`` / ``..`` and
              backslashes, and rejects absolute or parent-escaping paths so a
              denied location cannot be reached by traversal/indirection.
              """
              p = path.strip()
              # git unified-diff prefixes.
              for pre in ("a/", "b/"):
                  if p.startswith(pre):
                      p = p[len(pre):]
                      break
              p = p.replace("\\", "/")
              # normpath then re-POSIX it.
              norm = posixpath.normpath(p)
              if norm.startswith("/") or norm == ".." or norm.startswith("../"):
                  raise ValueError(f"path escapes repo root: {path!r}")
              return norm

          def parse_touched_paths(diff_text: str) -> set[str]:
              """Extract every path a unified diff adds/modifies/renames/deletes.

              Reads ``+++ ``/``--- `` targets, ``diff --git a/x b/y`` headers, and
              ``rename from/to`` lines — so a rename INTO a denied path (or a new
              file generated into one) is caught, not just in-place edits.
              """
              touched: set[str] = set()
              for line in diff_text.splitlines():
                  m = re.match(r"^diff --git (\S+) (\S+)$", line)
                  if m:
                      for raw in (m.group(1), m.group(2)):
                          touched.add(canonical(raw))
                      continue
                  m = re.match(r"^(?:\+\+\+|---) (.+)$", line)
                  if m:
                      tgt = m.group(1).strip()
                      if tgt == "/dev/null":
                          continue
                      # strip trailing tab-timestamp some diffs carry.
                      tgt = tgt.split("\t", 1)[0]
                      touched.add(canonical(tgt))
                      continue
                  m = re.match(r"^rename (?:from|to) (.+)$", line)
                  if m:
                      touched.add(canonical(m.group(1).strip()))
              return touched

          def find_symlink_additions(diff_text: str) -> list[tuple[str, str]]:
              """Return ``[(path, target)]`` for every symlink the diff creates.

              A symlink shows as git file mode ``120000``; its link target is the
              single added content line. Textual path canonicalization (``canonical``)
              cannot see a symlink that redirects a later in-diff write into a denied
              location (e.g. ``sub/link -> ../.github/workflows`` then a write to
              ``sub/link/evil.yml``). A candidate auto-build diff has no legitimate
              reason to introduce a symlink, so guard treats ANY symlink addition as
              a hard reject (boundary 2), closing the symlink-escape vector.
              """
              additions: list[tuple[str, str]] = []
              cur_path: str | None = None
              pending = False
              for line in diff_text.splitlines():
                  g = re.match(r"^diff --git (\S+) (\S+)$", line)
                  if g:
                      cur_path, pending = g.group(2), False
                      continue
                  p = re.match(r"^\+\+\+ (.+)$", line)
                  if p and p.group(1).strip() != "/dev/null":
                      cur_path = p.group(1).split("\t", 1)[0].strip()
                      continue
                  if re.match(r"^(?:new file mode|new mode) 120000\s*$", line):
                      pending = True
                      continue
                  if pending and line.startswith("+") and not line.startswith("+++"):
                      try:
                          path_c = canonical(cur_path) if cur_path else "<unknown>"
                      except ValueError:
                          # canonical() rejected the path (absolute/escaping); report
                          # it with only the git a//b/ PREFIX removed for the error
                          # message (re.sub, not str.lstrip which strips a char set).
                          path_c = re.sub(r"^[ab]/", "", cur_path or "<unknown>")
                      additions.append((path_c, line[1:].strip()))
                      pending = False
              return additions

          _GLOB_META = set("*?[]")
          _GLOB_RE_CACHE: dict[str, "re.Pattern[str]"] = {}

          def _glob_to_regex(glob: str) -> "re.Pattern[str]":
              """Compile a gitignore-style glob to a '/'-aware, case-insensitive regex.

              Python's ``fnmatch`` does NOT implement recursive ``**`` (it treats it
              as a single ``*`` that already spans ``/``), so ``**/template.yaml``
              fails to match a repo-ROOT ``template.yaml`` — a denylist bypass for
              exactly the IaC/secret families boundary 2 must catch. This translates
              ``**/`` to "any depth INCLUDING zero", ``**`` to ".*", ``*`` to a single
              non-slash run, ``?`` to one non-slash char, and matches case-
              insensitively (POSIX runners are case-sensitive, but a case variant of a
              trust-control filename must not slip the gate).
              """
              cached = _GLOB_RE_CACHE.get(glob)
              if cached is not None:
                  return cached
              out: list[str] = []
              i, n = 0, len(glob)
              while i < n:
                  if glob[i : i + 3] == "**/":
                      out.append(r"(?:.*/)?")
                      i += 3
                  elif glob[i : i + 2] == "**":
                      out.append(r".*")
                      i += 2
                  elif glob[i] == "*":
                      out.append(r"[^/]*")
                      i += 1
                  elif glob[i] == "?":
                      out.append(r"[^/]")
                      i += 1
                  else:
                      out.append(re.escape(glob[i]))
                      i += 1
              pat = re.compile("^" + "".join(out) + "$", re.IGNORECASE)
              _GLOB_RE_CACHE[glob] = pat
              return pat

          def denied(path: str) -> bool:
              """True if ``path`` is on the trust-control denylist (recursive, case-insensitive)."""
              return any(_glob_to_regex(g).match(path) for g in DENY_GLOBS)

          def _scope_prefix(entry: str) -> str | None:
              """Reduce a canonicalized scope entry to a concrete dir/file prefix.

              Declared scope is *confinement*, not a pattern that may widen coverage.
              ``fnmatch``-ing scope let a single ``**`` (or ``*``) entry match the
              whole tree, collapsing boundary 2b to a no-op. Instead we take the
              leading path segments up to the first glob metacharacter and prefix
              -match against them (mirrors the box-side ``_in_scope``). A scope that
              begins with a metacharacter reduces to the empty (repo-root) prefix and
              is dropped, so it can never widen to everything.
              """
              keep: list[str] = []
              for part in entry.split("/"):
                  if any(c in _GLOB_META for c in part):
                      break
                  keep.append(part)
              prefix = "/".join(keep)
              return prefix or None

          def safe_scope(scope: list[str]) -> list[str]:
              """Canonicalize scope into concrete path prefixes; drop escaping/empty.

              An absolute or parent-escaping entry is discarded (canonical raises),
              and a glob that reduces to the repo root is dropped, so a malformed or
              over-broad scope can only SHRINK what is allowed, never widen it.
              """
              safe: list[str] = []
              for g in scope:
                  try:
                      canon = canonical(g)
                  except ValueError:
                      continue
                  prefix = _scope_prefix(canon)
                  if prefix is not None and prefix not in safe:
                      safe.append(prefix)
              return safe

          def in_scope(path: str, scope: list[str]) -> bool:
              """True if ``path`` is at or under one of the declared scope prefixes."""
              return any(path == entry or path.startswith(entry + "/") for entry in scope)

          def main() -> int:
              diff_path = os.environ["DIFF_PATH"]
              expected = os.environ["EXPECTED_DIFF_HASH"].strip().lower()
              scope = [s for s in os.environ.get("DECLARED_SCOPE", "").splitlines() if s.strip()]

              with open(diff_path, "rb") as fh:
                  raw = fh.read()
              actual = hashlib.sha256(raw).hexdigest()

              # Boundary 3: integrity. A tampered/substituted diff fails here.
              if actual != expected:
                  print(f"::error::diff hash mismatch: expected={expected} actual={actual}")
                  return 2

              # Fail CLOSED on a non-UTF-8 diff rather than silently replacing bytes
              # (errors='replace' could let a homoglyph/encoding trick evade the path
              # match). A legitimate diff over source is valid UTF-8.
              try:
                  text = raw.decode("utf-8")
              except UnicodeDecodeError as exc:
                  print(f"::error::diff is not valid UTF-8 ({exc}); refusing to parse")
                  return 8

              touched = parse_touched_paths(text)
              if not touched:
                  print("::error::no paths parsed from diff; refusing empty/garbled diff")
                  return 3

              # Boundary 2a: trust-control denylist (CI-side HARD FAIL).
              hits = sorted(p for p in touched if denied(p))
              if hits:
                  for h in hits:
                      print(f"::error::trust-control-surface violation: {h}")
                  print("::error::diff touches the trust-control surface; escalate to human + GPT cross-review")
                  return 4

              # Boundary 2a': symlink escape. A symlink can redirect a later in-diff
              # write into a denied path that textual matching cannot see, so any
              # symlink addition is rejected outright.
              symlinks = find_symlink_additions(text)
              if symlinks:
                  for path, target in symlinks:
                      print(f"::error::diff introduces a symlink ({path} -> {target}); symlinks can redirect writes into denied paths and are not allowed in an auto-built diff")
                  print("::error::symlink in candidate diff; escalate to human + GPT cross-review")
                  return 7

              # Boundary 2b: declared-scope enforcement.
              if not scope:
                  print("::error::no declared scope provided; refusing unscoped diff")
                  return 5
              scope = safe_scope(scope)
              if not scope:
                  print("::error::declared scope has no valid (non-escaping) entries; refusing diff")
                  return 5
              out_of_scope = sorted(p for p in touched if not in_scope(p, scope))
              if out_of_scope:
                  for p in out_of_scope:
                      print(f"::error::out-of-declared-scope path: {p}")
                  return 6

              gh_out = os.environ.get("GITHUB_OUTPUT")
              if gh_out:
                  with open(gh_out, "a", encoding="utf-8") as fh:
                      fh.write(f"diff_hash={actual}\n")
              print(f"diff_hash={actual}")
              print(f"validated {len(touched)} path(s); all in-scope, none on the trust-control surface")
              return 0

          sys.exit(main())
          PY

  # ───────────────────────────────────────────────────────────────────────────
  # JOB 2 — build-test (boundary 1). UNTRUSTED execution. This is the ONLY job
  # that applies + runs the patch. It is credential-less: contents:read only, no
  # secrets, no OIDC, no write token, egress blocked. There is nothing here to
  # steal and nothing to assume. It writes a report artifact consumed by the
  # privileged gate as DATA — that report is NOT authoritative (boundary 4).
  # Depends on `guard` so a denied/tampered diff never reaches execution.
  # ───────────────────────────────────────────────────────────────────────────
  build-test:
    needs: guard
    runs-on: ubuntu-latest
    timeout-minutes: 20
    permissions:
      contents: read
    steps:
      - name: Harden runner (block egress — untrusted code runs here)
        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
        with:
          # Block, not audit: this is where untrusted patch code executes. A
          # narrow allowlist for dependency resolution only; everything else is
          # denied so a prompt-injected patch cannot phone home.
          # DEPLOY: this allowlist is GitHub + PyPI only. Before enabling this
          # workflow for a repo, replace/extend it with EXACTLY that repo's
          # package registries (npm, crates, Go proxy, ...) and nothing more —
          # an over-broad allowlist weakens the egress boundary.
          egress-policy: block
          allowed-endpoints: >
            github.com:443
            api.github.com:443
            objects.githubusercontent.com:443
            codeload.github.com:443
            pypi.org:443
            files.pythonhosted.org:443

      - name: Checkout base repo (clean ref; patch applied on top after)
        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          # Checkout carries NO token into the working tree usable for writes —
          # this job's permissions are contents:read. persist-credentials:false
          # guarantees the patch cannot reuse the checkout token.
          persist-credentials: false

      - name: Re-download candidate diff (re-validated below)
        uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4.1.8
        with:
          name: ${{ inputs.diff_artifact_name }}
          path: ./_incoming

      - name: Re-verify diff hash before apply (defense-in-depth)
        env:
          EXPECTED_DIFF_HASH: ${{ needs.guard.outputs.diff_hash }}
          DIFF_PATH: ./_incoming/candidate.diff
        run: |
          set -euo pipefail
          # Independently confirm the bytes match the hash `guard` blessed, so a
          # swapped artifact between jobs cannot slip an unvetted diff into the
          # apply step.
          python3 - <<'PY'
          from __future__ import annotations

          import hashlib
          import os
          import sys

          def main() -> int:
              expected = os.environ["EXPECTED_DIFF_HASH"].strip().lower()
              with open(os.environ["DIFF_PATH"], "rb") as fh:
                  actual = hashlib.sha256(fh.read()).hexdigest()
              if actual != expected:
                  print(f"::error::pre-apply hash mismatch: expected={expected} actual={actual}")
                  return 1
              print(f"diff hash confirmed: {actual}")
              return 0

          sys.exit(main())
          PY

      - name: Apply candidate diff (UNTRUSTED — credential-less sandbox)
        run: |
          set -euo pipefail
          # --check first so a malformed diff fails cleanly; then apply. The
          # working tree has no write credential, so applying + running it can
          # touch only this ephemeral runner.
          git apply --check ./_incoming/candidate.diff
          git apply ./_incoming/candidate.diff

      - name: Set up Python
        uses: actions/setup-python@0b93645e9fea7318ecaed2b359559ac225c90a2b # v5.3.0
        with:
          python-version: "3.12"

      - name: Install + build + test (untrusted; result is non-authoritative)
        id: run
        run: |
          set -euo pipefail
          # Placeholder build/test for the narrowest task class (dep bump /
          # single-file fix). At deploy time this is parameterized per target
          # repo. Exit code is what matters; any file the patch writes is
          # ignored by the authoritative gate (boundary 4).
          if [ -f requirements.txt ]; then
            python3 -m pip install --quiet -r requirements.txt || true
          fi
          python3 -m pip install --quiet ruff pytest || true
          ruff check . || echo "ruff non-zero (recorded, non-authoritative)"
          pytest -q || echo "pytest non-zero (recorded, non-authoritative)"

      - name: Emit non-authoritative report (job conclusion is the truth)
        if: always()
        run: |
          set -euo pipefail
          # This report is consumed by the gate as DATA for the verifier agent's
          # next-fix reasoning. It is NOT the pass/fail decision — the gate reads
          # the AUTHENTICATED job conclusion (boundary 4), never this file.
          mkdir -p ./_report
          printf '{"task_id":"%s","note":"non-authoritative; gate uses job conclusion"}\n' \
            "${{ inputs.task_id }}" > ./_report/report.json

      - name: Upload non-authoritative report
        if: always()
        uses: actions/upload-artifact@b4b15b8c7c6ac21ea08fcf65892d2ee8f75cf882 # v4.4.3
        with:
          name: build-test-report-${{ inputs.task_id }}
          path: ./_report/report.json
          retention-days: 7

  # ───────────────────────────────────────────────────────────────────────────
  # JOB 3 — gate-and-pr (boundaries 1 + 4 + 5). PRIVILEGED, but it NEVER checks
  # out or executes patch-controlled code. It reads the AUTHENTICATED conclusion
  # of `build-test` (via needs.*.result — GitHub-controlled, patch-independent)
  # keyed to this run, and only on a clean pass opens a DRAFT PR. It never trusts
  # any artifact the patch wrote. Pass/fail is pure code here, not the LLM.
  #
  # NOTE: the OIDC/write grant is declared here as the eventual home of the
  # privileged step, but this file is deploy-gated — the `id-token`/PR-open
  # step is left as a documented placeholder so nothing is provisioned until the
  # §3.3.2 review gates pass. Wiring the real OIDC role is Phase P3 / Phase 5
  # AFTER the mandatory GPT-4.1 cross-review of the IAM.
  # ───────────────────────────────────────────────────────────────────────────
  gate-and-pr:
    needs: [guard, build-test]
    # `always()` so the gate runs even when build-test failed, to record the
    # authoritative conclusion. The gate itself decides pass/fail from results.
    if: always()
    runs-on: ubuntu-latest
    timeout-minutes: 5
    permissions:
      contents: read
      # pull-requests: write    # ← enabled ONLY after the §3.3.2 review gates.
      # id-token: write         # ← OIDC for the Option-B apply role, post-gate.
    steps:
      - name: Harden runner (privileged job; block egress)
        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
        with:
          egress-policy: block
          allowed-endpoints: >
            github.com:443
            api.github.com:443

      - name: Pure-code pass/fail gate over authenticated results
        env:
          # These come from GitHub's job orchestration, NOT from the patch.
          GUARD_RESULT: ${{ needs.guard.result }}
          BUILD_TEST_RESULT: ${{ needs.build-test.result }}
          DIFF_HASH: ${{ needs.guard.outputs.diff_hash }}
          EXPECTED_DIFF_HASH: ${{ inputs.expected_diff_hash }}
          RUN_ID: ${{ github.run_id }}
        run: |
          set -euo pipefail
          # Deterministic, patch-independent decision. Consumes ONLY the
          # authenticated needs.*.result values + the hash binding (all from
          # GitHub's orchestration, never from a file the patch wrote). Mirrors
          # secrev's "one pure-code script owns the block decision." The
          # verifier AGENT only reads failures to propose a fix; it cannot
          # declare success here.
          python3 - <<'PY'
          from __future__ import annotations

          import os
          import sys

          def gate(
              *,
              guard_result: str,
              build_test_result: str,
              diff_hash: str,
              expected_hash: str,
              run_id: str,
          ) -> tuple[bool, str]:
              """Return (passed, reason) from authenticated, patch-independent inputs.

              A pass requires: the guard job succeeded (integrity + denylist +
              scope all held), the build-test job succeeded, and the hash the
              guard exported equals the ledger-recorded expected hash bound to
              this run. Anything else blocks.
              """
              if not run_id:
                  return False, "missing run id; cannot bind decision to a run"
              if diff_hash.strip().lower() != expected_hash.strip().lower():
                  return False, f"hash binding broken: guard={diff_hash} expected={expected_hash}"
              if guard_result != "success":
                  return False, f"guard did not pass: {guard_result!r}"
              if build_test_result != "success":
                  return False, f"build-test did not pass: {build_test_result!r}"
              return True, "authenticated build/test passed and diff hash is bound"

          def main() -> int:
              passed, reason = gate(
                  guard_result=os.environ.get("GUARD_RESULT", ""),
                  build_test_result=os.environ.get("BUILD_TEST_RESULT", ""),
                  diff_hash=os.environ.get("DIFF_HASH", ""),
                  expected_hash=os.environ.get("EXPECTED_DIFF_HASH", ""),
                  run_id=os.environ.get("RUN_ID", ""),
              )
              if passed:
                  print(f"GATE PASS: {reason}")
                  if (gh_out := os.environ.get("GITHUB_OUTPUT")):
                      with open(gh_out, "a", encoding="utf-8") as fh:
                          fh.write("gate=pass\n")
                  return 0
              print(f"::error::GATE BLOCK: {reason}")
              return 1

          sys.exit(main())
          PY

      - name: Open DRAFT PR (DEPLOY-GATED PLACEHOLDER — not enabled)
        if: ${{ false }} # ← hard-disabled. Enable only after §3.3.2 review gates.
        run: |
          echo "Draft-PR open runs here AFTER the mandatory GPT-4.1 cross-review"
          echo "+ /sh-security-review of this workflow and its OIDC role."
          echo "Draft PR only; never auto-merge (D2). Branch protection is the"
          echo "final enforcement (boundary 5)."