Add CodeQL SAST workflow

.github/workflows/codeql.yml

@@ -0,0 +1,50 @@
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+  schedule:
+    - cron: '30 2 * * 1'  # Weekly on Monday at 2:30 AM
+
+permissions:
+  contents: read
+
+jobs:
+  analyze:
+    name: Analyze (${{ matrix.language }})
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'c-cpp' ]
+
+    steps:
+    - name: Harden Runner
+      uses: step-security/harden-runner@v2
+      with:
+        egress-policy: audit
+
+    - name: Checkout repository
+      uses: actions/checkout@v4
+
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v4
+      with:
+        languages: ${{ matrix.language }}
+        build-mode: none
+        # Use 'none' for kernel drivers - no compilation needed for static analysis
+        # This is faster and works without full kernel build environment
+        queries: security-and-quality
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v4
+      with:
+        category: "/language:${{matrix.language}}"
+        upload: true