docs(workflow): require branch deletion after rebase-merge

scripts/openclaw-upstream-workflow.md

@@ -30,6 +30,31 @@ Then:
 - Preferred PR strategy: **Rebase and merge**
 - Avoid merge commits unless explicitly required for a special case
 
+## Post-merge branch cleanup (required)
+
+After PR merge, delete the branch on both remote and local:
+
+```bash
+# from repo root
+
+git checkout main
+git pull --rebase
+
+# delete remote branch
+
+git push origin --delete <branch-name>
+
+# delete local branch
+
+git branch -d <branch-name>
+```
+
+If branch was not merged cleanly and Git blocks deletion, inspect first; only then force-delete local branch with:
+
+```bash
+git branch -D <branch-name>
+```
+
 ## Branch naming
 
 - `fix/...` for bugfixes