ci: add CodeQL analysis workflow configuration

.github/workflows/codeql.yml

@@ -0,0 +1,57 @@
+name: "CodeQL Advanced"
+
+on:
+  push:
+    branches: ["main"]
+  pull_request:
+    branches: ["main"]
+  schedule:
+    - cron: "32 13 * * 0"
+
+jobs:
+  analyze:
+    name: Analyze (${{ matrix.language }})
+    # Runner size impacts CodeQL analysis time. To learn more, please see:
+    #   - https://gh.io/recommended-hardware-resources-for-running-codeql
+    #   - https://gh.io/supported-runners-and-hardware-resources
+    #   - https://gh.io/using-larger-runners (GitHub.com only)
+    # Consider using larger runners or machines with greater resources for possible analysis time improvements.
+    runs-on: ubuntu-latest
+    permissions:
+      # required for all workflows
+      security-events: write
+
+      # required to fetch internal or private CodeQL packs
+      packages: read
+
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - language: actions
+            build-mode: none
+          - language: csharp
+            build-mode: none
+            # Using 'none' because Unity SDK packages don't include .csproj/.sln files.
+            # CodeQL autobuild cannot detect build scripts for Unity packages.
+            # Lower quality metrics (66% call targets, 79% type resolution) are acceptable
+            # for static analysis of Unity SDK code without a full build context.
+          # c-cpp and Swift analysis removed: Unity SDKs don't include build projects in the repo
+          # (Unity generates Xcode/Android projects during build). CodeQL's C/C++ autobuilder
+          # doesn't recognize .mm (Objective-C++) files as source files. The minimal native
+          # bridge code is low-risk, and the main codebase (C#) is already being analyzed.
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+
+      # Initializes the CodeQL tools for scanning.
+      - 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}}"