Add scheduled CodeQL scanning

.github/workflows/codeql.yml

@@ -0,0 +1,54 @@
+name: CodeQL
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+  schedule:
+    - cron: "23 7 * * 3"
+  workflow_dispatch:
+
+permissions:
+  actions: read
+  contents: read
+  packages: read
+  security-events: write
+
+jobs:
+  analyze:
+    name: Analyze (${{ matrix.language }})
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - language: javascript-typescript
+            build-mode: none
+          - language: csharp
+            build-mode: manual
+
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+
+      - name: Setup .NET
+        if: matrix.language == 'csharp'
+        uses: actions/setup-dotnet@a98b56852c35b8e3190ac28c8c2271da59106c68 # v6.0.0
+        with:
+          global-json-file: global.json
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@b96794f015dfd88f77b49b1c93e0fa7110f94c63 # v4.38.0
+        with:
+          languages: ${{ matrix.language }}
+          build-mode: ${{ matrix.build-mode }}
+
+      - name: Build C# solution
+        if: matrix.language == 'csharp'
+        # CodeQL needs compiler extraction, not the Aspire orchestration bundle.
+        run: dotnet build Aspire.Dev.slnx --configuration Release -p:AspireUseCliBundle=false
+
+      - name: Perform CodeQL analysis
+        uses: github/codeql-action/analyze@b96794f015dfd88f77b49b1c93e0fa7110f94c63 # v4.38.0
+        with:
+          category: "/language:${{ matrix.language }}"