chore: update pr template

Author: gusye1234

.github/PULL_REQUEST_TEMPLATE.md

@@ -6,6 +6,17 @@ Please ensure your pull request meets the following requirements:
 - [ ] PR Task 2
 - [ ] ...
 
+# Impact Areas
+Which part of Acontext would this feature affect?
+- [ ] Client SDK (Python)
+- [ ] Client SDK (TypeScript)
+- [ ] Core Service
+- [ ] API Server
+- [ ] Dashboard
+- [ ] CLI Tool
+- [ ] Documentation
+- [ ] Other: please_specify_here
+
 # Checklist
 - [ ] Open your pull request against the `dev` branch.
 - [ ] All tests pass in available continuous integration systems (e.g., GitHub Actions).