feat: Add InputModule Phase 1 + IT_015 integration tests
Complete implementation of InputModule with SDL2 backend for mouse and keyboard input, plus UIModule integration tests.
## InputModule Features
- Mouse input capture (position, buttons, wheel)
- Keyboard input capture (keys, modifiers)
- SDL2 backend implementation
- IIO topic publishing (input🐭*, input⌨️*)
- Hot-reload compatible module structure
## Integration Tests (IT_015)
- IT_015_input_ui_integration: Full UIModule + IIO input test
- IT_015_minimal: Minimal IIO-only message publishing test
- Visual test_30: InputModule interactive showcase
## Known Issues
- Tests compile successfully but cannot run due to MinGW/Windows runtime DLL initialization error (0xC0000139)
- Workaround: Use VSCode debugger or native Windows execution
- See tests/integration/IT_015_STATUS.md for details
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
StillHammer
21590418f1