chore(security): harden GitHub workflows

.github/workflows/actionlint.yml

@@ -4,6 +4,10 @@ on: [push, pull_request]
 permissions:
   contents: read
 
+concurrency:
+  group: actionlint-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   actionlint:
     runs-on: ubicloud-standard-8

.github/workflows/ci-image.yml

@@ -16,6 +16,10 @@ on:
   # Manual trigger
   workflow_dispatch:
 
+concurrency:
+  group: ci-image
+  cancel-in-progress: false
+
 jobs:
   build:
     runs-on: ubicloud-standard-8

.github/workflows/dependency-review.yml

@@ -0,0 +1,21 @@
+name: Dependency Review
+
+on:
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+
+concurrency:
+  group: dependency-review-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  dependency-review:
+    runs-on: ubuntu-24.04
+    steps:
+      - name: Review dependency changes
+        uses: actions/dependency-review-action@2031cfc080254a8a887f58cffee85186f0e49e48 # v4.9.0
+        with:
+          fail-on-severity: high

.github/workflows/osv-scanner.yml

@@ -0,0 +1,26 @@
+name: OSV Scanner
+
+on:
+  schedule:
+    - cron: '23 7 * * 1'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: osv-scanner
+  cancel-in-progress: true
+
+jobs:
+  scan:
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+    uses: google/osv-scanner-action/.github/workflows/osv-scanner-reusable.yml@3adb4b14a2b0623876d18d863a498b785fb3752d # v2.3.8
+    with:
+      scan-args: |-
+        --include-git-root
+        --recursive
+        ./

.github/workflows/quality-gate.yml

@@ -10,6 +10,10 @@ on:
 permissions:
   contents: read
 
+concurrency:
+  group: quality-gate-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   quality:
     runs-on: ubuntu-24.04

.github/workflows/scorecard.yml

@@ -0,0 +1,46 @@
+name: OpenSSF Scorecard
+
+on:
+  branch_protection_rule:
+  schedule:
+    - cron: '41 7 * * 1'
+  push:
+    branches: [main]
+
+permissions:
+  contents: read
+
+concurrency:
+  group: scorecard-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  analysis:
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: read
+      security-events: write
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+        with:
+          persist-credentials: false
+
+      - name: Run Scorecard analysis
+        uses: ossf/scorecard-action@4eaacf0543bb3f2c246792bd56e8cdeffafb205a # v2.4.3
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          publish_results: false
+
+      - name: Upload Scorecard results to code scanning
+        uses: github/codeql-action/upload-sarif@85b88275909735f5bc23196090e03d2eb148b3de # v3.32.4
+        with:
+          sarif_file: results.sarif
+
+      - name: Upload Scorecard results artifact
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        with:
+          name: scorecard-results
+          path: results.sarif
+          retention-days: 5

.github/workflows/skill-docs.yml

@@ -4,6 +4,10 @@ on: [push, pull_request]
 permissions:
   contents: read
 
+concurrency:
+  group: skill-docs-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   check-freshness:
     runs-on: ubicloud-standard-8

test/release-hardening.test.ts

@@ -12,6 +12,7 @@ describe("release and CI hardening", () => {
     for (const name of fs.readdirSync(workflowRoot).filter((entry) => entry.endsWith(".yml"))) {
       const source = fs.readFileSync(path.join(workflowRoot, name), "utf8");
       expect(source, `${name} must declare top-level permissions`).toMatch(/^permissions:\s*$/m);
+      expect(source, `${name} must declare workflow concurrency`).toMatch(/^concurrency:\s*$/m);
       for (const match of source.matchAll(/\buses:\s*[^\s@]+@([^\s#]+)/g)) {
         expect(match[1], `${name} contains a mutable action ref`).toMatch(/^[a-f0-9]{40}$/);
       }
@@ -24,6 +25,24 @@ describe("release and CI hardening", () => {
     expect(source.match(new RegExp(guard.replaceAll(".", "\\."), "g"))?.length).toBeGreaterThanOrEqual(3);
   });
 
+  test("public dependency and repository security workflows stay enabled and least-privileged", () => {
+    const dependencyReview = read(".github/workflows/dependency-review.yml");
+    expect(dependencyReview).toContain("actions/dependency-review-action@");
+    expect(dependencyReview).toContain("fail-on-severity: high");
+    expect(dependencyReview).not.toContain("pull_request_target:");
+
+    const osv = read(".github/workflows/osv-scanner.yml");
+    expect(osv).toContain("google/osv-scanner-action/.github/workflows/osv-scanner-reusable.yml@");
+    expect(osv).toContain("security-events: write");
+    expect(osv).toContain("schedule:");
+
+    const scorecard = read(".github/workflows/scorecard.yml");
+    expect(scorecard).toContain("ossf/scorecard-action@");
+    expect(scorecard).toContain("github/codeql-action/upload-sarif@");
+    expect(scorecard).toContain("publish_results: false");
+    expect(scorecard).not.toContain("id-token: write");
+  });
+
   test("npm package is an explicit small runtime-control surface", () => {
     const pkg = JSON.parse(read("package.json"));
     expect(pkg.version).toBe(read("VERSION").trim());