ci: harden workflows per Hypatia security-scan findings

Address the actionable, in-scope items from the advisory Hypatia scan
by mirroring the canonical estate templates from sibling repos
(ochrance-framework / valence-shell):

- Add codeql.yml (mirrors ochrance-framework: javascript-typescript,
  build-mode none; SHA-pinned actions). Analyses the repo's committed
  JS (tools/banner/build-banner.mjs); distinct SARIF category from the
  advisory Hypatia scan.
- Add secret-scanner.yml (calls the estate secret-scanner-reusable,
  SHA-pinned).
- governance.yml: pin the governance-reusable workflow to a SHA instead
  of @main (matches mirror.yml / scorecard.yml and the sibling repos'
  pin), closing the unpinned-action finding.
- agda.yml (check, cold-check) and hypatia-scan.yml (scan): add
  timeout-minutes to the real-step jobs, bounding runaway jobs below the
  6-hour default.

Deliberately NOT changed (documented in the PR):
- timeout-minutes is NOT added to governance.yml / mirror.yml /
  scorecard.yml — those are reusable-workflow callers, where job-level
  timeout-minutes is invalid YAML; the timeout belongs in the reusable
  workflow (hyperpolymath/standards).
- No synthetic test directory for the "no tests" finding — the Agda
  proof suite (All.agda / Smoke.agda / characteristic / examples,
  typechecked in agda.yml) is the verification suite.

The Hypatia scan is advisory (non-gating) per hypatia-scan.yml.

https://claude.ai/code/session_01Jxr3Wy4ngpkbc2QwjEam82

Author: claude

.github/workflows/agda.yml

@@ -27,6 +27,10 @@ permissions: read-all
 jobs:
   check:
     runs-on: ubuntu-latest
+    # Bound the job so a hung typecheck/clone cannot occupy a runner for
+    # the 6-hour default. Generous upper bound — the warm suite is a few
+    # minutes; a cold stdlib+suite build is well under this.
+    timeout-minutes: 30
     steps:
       - name: Checkout
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
@@ -148,6 +152,9 @@ jobs:
     # given the documented WSL git-object-corruption risk). Runs in
     # parallel with `check`; both must pass.
     runs-on: ubuntu-latest
+    # Cold (--ignore-interfaces) build is the slowest path; still well
+    # under this bound. Caps a runaway/hung job below the 6-hour default.
+    timeout-minutes: 30
     steps:
       - name: Checkout
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2

.github/workflows/codeql.yml

@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: MPL-2.0
+name: CodeQL Security Analysis
+
+on:
+  push:
+    branches: [main, master]
+  pull_request:
+    branches: [main, master]
+  schedule:
+    - cron: '0 6 * * 1'
+
+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR
+# updates do not pile up queued runs against the shared account-wide
+# Actions concurrency pool. Applied only to read-only check workflows
+# (no publish/mutation), so cancelling a superseded run is always safe.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  analyze:
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    permissions:
+      contents: read
+      security-events: write
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - language: javascript-typescript
+            build-mode: none
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@c6f931105cb2c34c8f901cc885ba1e2e259cf745 # v3
+        with:
+          languages: ${{ matrix.language }}
+          build-mode: ${{ matrix.build-mode }}
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@c6f931105cb2c34c8f901cc885ba1e2e259cf745 # v3
+        with:
+          category: "/language:${{ matrix.language }}"

.github/workflows/governance.yml

@@ -30,4 +30,8 @@ permissions:
 
 jobs:
   governance:
-    uses: hyperpolymath/standards/.github/workflows/governance-reusable.yml@main
+    # Pinned to a SHA (not @main) per the estate supply-chain policy —
+    # matches the sibling repos' pin (e.g. ochrance-framework). Bump
+    # deliberately, never float: an unpinned reusable workflow is an
+    # unpinned trust boundary. mirror.yml / scorecard.yml already pin.
+    uses: hyperpolymath/standards/.github/workflows/governance-reusable.yml@861b5e911d9e5dcfb3c0ab3dd2a9a3c8fd0a1613

.github/workflows/hypatia-scan.yml

@@ -43,6 +43,9 @@ jobs:
   scan:
     name: Hypatia Neurosymbolic Analysis
     runs-on: ubuntu-latest
+    # Bound the job: clone + Elixir build + scan is minutes, not hours.
+    # Caps a hung clone/build below the 6-hour default.
+    timeout-minutes: 20
 
     steps:
       - name: Checkout repository

.github/workflows/secret-scanner.yml

@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: MPL-2.0
+name: Secret Scanner
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  scan:
+    uses: hyperpolymath/standards/.github/workflows/secret-scanner-reusable.yml@3e4bd4c93911750727e2e4c66dff859e00079da0
+    secrets: inherit