fix(tui): prevent mouse movement events from corrupting input on Windows

[szmania]

This PR addresses an issue where using the TUI on Windows would cause strange characters to appear in the input prompt after several interactions. The problem was caused by mouse movement tracking signals from the terminal that were not being properly handled, resulting in ANSI escape codes being printed as text.

The fix adds an on_mouse_move event handler to the TUI application that specifically stops mouse movement events on Windows. This prevents the problematic signals from reaching the input processing while preserving all other mouse functionality including scrolling and clicking.

Changes:

• Added on_mouse_move method in cecli/tui/app.py that calls event.stop() on Windows
• Added comprehensive tests in tests/tui/test_app.py to verify:
  • Mouse move events are stopped on Windows
  • Mouse move events are not stopped on other platforms (Linux/macOS)

Testing:
The new tests ensure the fix works correctly on Windows without affecting the behavior on other operating systems. The tests use pytest and mock the platform system to verify the conditional logic.

Impact:

• Windows users will no longer experience corrupted input prompts
• All other mouse functionality (scrolling, clicking) remains intact
• No changes to behavior on non-Windows platforms