Add CodeQL Advanced GitHub Actions workflow

Introduce a CodeQL analysis workflow (CodeQL Advanced) that runs on push, pull_request, and a weekly schedule. It initializes and runs github/codeql-action for a matrix of languages (actions, go, javascript-typescript), configures build-mode per-language, sets minimal read/write permissions for security-events, packages, actions and contents, and selects macOS for Swift or Ubuntu otherwise.

.github/workflows/codeql.yml

@@ -0,0 +1,43 @@
+name: "CodeQL Advanced"
+
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron: '18 2 * * 2'
+
+jobs:
+  analyze:
+    name: Analyze (${{ matrix.language }})
+    runs-on: ${{ (matrix.language == 'swift' && 'macos-latest') || 'ubuntu-latest' }}
+    permissions:
+      security-events: write
+      packages: read
+      actions: read
+      contents: read
+
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+        - language: actions
+          build-mode: none
+        - language: go
+          build-mode: autobuild
+        - language: javascript-typescript
+          build-mode: none
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v4
+      with:
+        languages: ${{ matrix.language }}
+        build-mode: ${{ matrix.build-mode }}
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v4
+      with:
+        category: "/language:${{matrix.language}}"