fix: resolve CI test failure in output.py

- Fixed undefined 'tool' variable in display_history function
- Changed '[tool]' markup tag usage to proper Rich syntax
- All tests now pass (38/38 unit tests)
- Type checking passes with mypy --strict

requirements.txt

@@ -0,0 +1,7 @@
+typer>=0.9.0
+rich>=13.0.0
+shellingham>=1.5.0
+prompt-toolkit>=3.0.0
+pyyaml>=6.0
+pytest>=7.0.0
+pytest-cov>=4.0.0