feat: add Claude-Gemini collaboration and chat capabilities

- Add collaboration demo showing dynamic context requests
- Implement chat tool for general conversations and brainstorming
- Add tool selection guide with clear boundaries
- Introduce models configuration system
- Update prompts for better tool descriptions
- Refactor server to remove redundant functionality
- Add comprehensive tests for collaboration features
- Enhance base tool with collaborative features

This enables Claude to request additional context from Gemini
during tool execution, improving analysis quality and accuracy.

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

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

tests/test_thinking_modes.py

@@ -62,7 +62,12 @@ class TestThinkingModes:
         args = mock_create_model.call_args[0]
         assert args[2] == "minimal"  # thinking_mode parameter
 
-        assert result[0].text.startswith("Analysis:")
+        # Parse JSON response
+        import json
+
+        response_data = json.loads(result[0].text)
+        assert response_data["status"] == "success"
+        assert response_data["content"].startswith("Analysis:")
 
     @pytest.mark.asyncio
     @patch("tools.base.BaseTool.create_model")