Fix all failing tests and pytest collection warnings

Fixed MagicMock comparison errors across multiple test suites by:
- Adding proper ModelCapabilities mocks with real values instead of MagicMock objects
- Updating test_auto_mode.py with correct provider mocking for model availability tests
- Updating test_thinking_modes.py with proper capabilities mocking in all thinking mode tests
- Updating test_tools.py with proper capabilities mocking for CodeReview and Analyze tools
- Fixing test_large_prompt_handling.py by adding proper provider mocking to prevent errors before large prompt detection

Fixed pytest collection warnings by:
- Renaming TestGenRequest to TestGenerationRequest to avoid pytest collecting it as a test class
- Renaming TestGenTool to TestGenerationTool to avoid pytest collecting it as a test class
- Updated all imports and references across server.py, tools/__init__.py, and test files

All 459 tests now pass without warnings or MagicMock comparison errors.

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

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

tools/__init__.py

@@ -8,7 +8,7 @@ from .codereview import CodeReviewTool
 from .debug import DebugIssueTool
 from .precommit import Precommit
 from .refactor import RefactorTool
-from .testgen import TestGenTool
+from .testgen import TestGenerationTool
 from .thinkdeep import ThinkDeepTool
 from .tracer import TracerTool
 
@@ -20,6 +20,6 @@ __all__ = [
     "ChatTool",
     "Precommit",
     "RefactorTool",
-    "TestGenTool",
+    "TestGenerationTool",
     "TracerTool",
 ]