feat: enable auto-fix for lint and formatting in CI workflow

Run eslint --fix and prettier --write before validation checks, automatically
committing any fixes back to the branch.

https://claude.ai/code/session_018gvgrGDfMYGubkhj9WGTQy

Author: claude

.github/workflows/ci.yml

@@ -20,13 +20,34 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          ref: ${{ github.head_ref || github.ref_name }}
+          token: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Install mise
         uses: jdx/mise-action@v2
 
       - name: Install dependencies
         run: npm ci
 
+      - name: Auto-fix lint issues
+        run: npm run lint:fix
+
+      - name: Auto-fix formatting issues
+        run: npm run check:fix
+
+      - name: Commit auto-fixes if any
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git add -A
+          if git diff --cached --quiet; then
+            echo "No auto-fix changes to commit"
+          else
+            git commit -m "chore: auto-fix lint and formatting issues"
+            git push
+          fi
+
       - name: Lint
         run: npm run lint