fix(ci): improve CodeQL analysis quality with Unity build

Use game-ci/unity-builder to compile Unity scripts before CodeQL
analysis. This provides proper type information and resolves the
"Low C# analysis quality" warning.

Signed-off-by: JasonXuDeveloper - 傑 <jason@xgamedev.net>
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: JasonXuDeveloper

.github/workflows/codeql.yml

@@ -35,16 +35,45 @@ jobs:
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
+        with:
+          lfs: true
+
+      - name: Cache Unity Library
+        uses: actions/cache@v4
+        with:
+          path: UnityProject/Library
+          key: Library-CodeQL-2022.3.55f1-${{ hashFiles('UnityProject/Packages/packages-lock.json') }}
+          restore-keys: |
+            Library-CodeQL-2022.3.55f1-
+            Library-CodeQL-
 
       - name: Initialize CodeQL
         uses: github/codeql-action/init@v4
         with:
           languages: csharp
           config-file: ./.github/codeql/codeql-config.yml
-          # Use security-and-quality queries for comprehensive analysis
           queries: security-and-quality
-          # Use buildless mode for Unity projects (no standard .NET build)
-          build-mode: none
+          build-mode: manual
+
+      # Compile Unity scripts to generate assemblies for CodeQL analysis
+      # Using unity-builder with a no-op build method just compiles scripts
+      - name: Compile Unity Scripts
+        uses: game-ci/unity-builder@v4
+        env:
+          UNITY_EMAIL: ${{ secrets.UNITY_EMAIL }}
+          UNITY_PASSWORD: ${{ secrets.UNITY_PASSWORD }}
+          UNITY_SERIAL: ${{ secrets.UNITY_SERIAL }}
+        with:
+          projectPath: UnityProject
+          unityVersion: 2022.3.55f1
+          targetPlatform: StandaloneLinux64
+          buildName: CodeQL
+          # Skip actual build, we just need script compilation
+          customParameters: -nographics -quit
+
+      - name: Return Unity license
+        uses: game-ci/unity-return-license@v2
+        if: always()
 
       - name: Perform CodeQL Analysis
         uses: github/codeql-action/analyze@v4