chore: import upstream snapshot with attribution

.github/workflows/security.yaml

@@ -0,0 +1,73 @@
+name: Security
+
+on:
+  pull_request:
+    branches:
+      - main
+  push:
+    branches:
+      - main
+  schedule:
+    - cron: "25 5 * * 1"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  dependency-review:
+    if: github.event_name == 'pull_request'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: read
+
+    steps:
+      - name: Dependency review
+        uses: actions/dependency-review-action@v4
+        with:
+          fail-on-severity: high
+
+  npm-audit:
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version-file: ".nvmrc"
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run npm audit (production dependencies)
+        run: npm audit --omit=dev --audit-level=high
+
+  codeql:
+    if: github.event_name != 'pull_request'
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v3
+        with:
+          languages: javascript-typescript
+
+      - name: Autobuild
+        uses: github/codeql-action/autobuild@v3
+
+      - name: Analyze
+        uses: github/codeql-action/analyze@v3