fix(ci): push lint fixes to branch ref instead of detached HEAD

actions/checkout on pull_request events checks out the merge commit,
leaving the runner in detached HEAD state. A plain 'git push' then
fails with exit 128 because there is no active branch to push to.

Fix: use 'git push origin HEAD:${HEAD_REF}' when github.head_ref is
set (PR context), falling back to plain 'git push' on direct pushes
to main where HEAD is always attached.

Author: yacosta738

.github/workflows/ci.yml

@@ -48,10 +48,24 @@ jobs:
         if: |
           !contains(github.actor, 'dependabot') &&
           (github.event_name != 'pull_request' || github.event.pull_request.head.repo.owner.login == github.repository_owner)
+        env:
+          HEAD_REF: ${{ github.head_ref }}
         run: |
           git config user.name "github-actions[bot]"
           git config user.email "github-actions[bot]@users.noreply.github.com"
-          git diff --quiet || (git add -A && git commit -m "chore(lint): biome auto-fix" && git push)
+          # actions/checkout leaves a detached HEAD on PR events; push back
+          # to the source branch explicitly using HEAD_REF when available.
+          if git diff --quiet; then
+            echo "No lint fixes needed."
+          else
+            git add -A
+            git commit -m "chore(lint): biome auto-fix"
+            if [ -n "$HEAD_REF" ]; then
+              git push origin "HEAD:${HEAD_REF}"
+            else
+              git push
+            fi
+          fi
 
   smoke:
     name: Smoke Test