Use system Node.js instead of downloading in workflows

Replace actions/setup-node with simple version checks to avoid "Text file busy" errors on self-hosted runners. This assumes Node.js is already installed on the runner.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.forgejo/workflows/code-quality.yml

@@ -16,10 +16,9 @@ jobs:
           fetch-depth: 0  # Full history for better analysis
           
       - name: Setup Node.js
-        uses: actions/setup-node@v4
-        with:
-          node-version: '20'
-          cache: 'npm'
+        run: |
+          node --version
+          npm --version
           
       - name: Install dependencies
         run: npm ci