- IssueTools.get_issue now returns IssueModel instead of JSON string
- PRTools.get_pull_request now returns PullRequestModel instead of JSON string
- PRTools.create_pull_request now returns PullRequestModel instead of JSON string
- PRTools.update_pull_request now returns PullRequestModel instead of JSON string
- All methods have proper return type hints and raise exceptions on error
- Updated tests to verify model objects are returned directly
- Marked issue 5.4 as resolved in bad_code.md