style: fix linting and formatting issues

- Run black formatter on all Python files
- Fix ruff linting issues:
  - Remove unused imports
  - Remove unused variables
  - Fix f-string without placeholders
- All 37 tests still pass
- Code quality improved for CI/CD compliance

🧹 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

tools/debug_issue.py

@@ -146,8 +146,6 @@ Focus on finding the root cause and providing actionable solutions."""
 
         return full_prompt
 
-    def format_response(
-        self, response: str, request: DebugIssueRequest
-    ) -> str:
+    def format_response(self, response: str, request: DebugIssueRequest) -> str:
         """Format the debugging response"""
         return f"Debug Analysis\n{'=' * 50}\n\n{response}"