Change release workflow to trigger on push instead of pull_request

The pull_request:closed event wasn't triggering. Switch to push event
which fires after PR is merged to main. Extract PR number from merge
commit message to check for release labels.

This should fix the automatic trigger issue.

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

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

Author: kompre

.github/workflows/release.yml

@@ -1,8 +1,7 @@
 name: Release
 
 on:
-  pull_request:
-    types: [closed]
+  push:
     branches: [main]
   workflow_dispatch:
     inputs:
@@ -13,7 +12,6 @@ on:
 
 jobs:
   check-release-label:
-    if: github.event_name == 'workflow_dispatch' || github.event.pull_request.merged == true
     runs-on: ubuntu-latest
     outputs:
       should-release: ${{ steps.check.outputs.release }}
@@ -27,11 +25,22 @@ jobs:
         env:
           GH_TOKEN: ${{ github.token }}
         run: |
-          # Get PR number from event or input
+          # Get PR number from event or commit message
           if [ "${{ github.event_name }}" == "workflow_dispatch" ]; then
             PR_NUMBER=${{ inputs.pr_number }}
           else
-            PR_NUMBER=${{ github.event.pull_request.number }}
+            # Extract PR number from merge commit message
+            COMMIT_MSG=$(git log -1 --pretty=%B)
+            PR_NUMBER=$(echo "$COMMIT_MSG" | grep -oP '(?<=#)\d+(?=\))' | head -1)
+
+            if [ -z "$PR_NUMBER" ]; then
+              echo "No PR number found in commit message, skipping release"
+              echo "release=false" >> $GITHUB_OUTPUT
+              echo "test=false" >> $GITHUB_OUTPUT
+              exit 0
+            fi
+
+            echo "Found PR number: $PR_NUMBER"
           fi
 
           LABELS=$(gh pr view $PR_NUMBER --json labels --jq '.labels[].name')