fix: add success condition to PR comment step in workflow

Co-authored-by: toolate28 <[email protected]>

Author: Copilot

.github/workflows/coding-agent.yml

@@ -45,7 +45,7 @@ jobs:
           echo "ATOM provenance tracked for ethical review"
 
       - name: Comment on PR
-        if: github.event_name == 'pull_request'
+        if: github.event_name == 'pull_request' && steps.simulate.outcome == 'success'
         uses: actions/github-script@v7
         with:
           script: |