- get_app_dir(): project root in dev, exe dir in PyInstaller bundle
- get_resource_path/get_config_path: paths under app dir
- get_log_dir/get_output_dir: auto-create and return logs/ and output/
- Refactor log_service to use get_log_dir() instead of own __file__ calc
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>