- Add NewWithLoader(loader, opts...) for custom storage backends
- Add Option type with WithFallback, WithFormality, WithHandlers,
WithDefaultHandlers, WithMode, WithDebug options
- Update New() and NewWithFS() to accept options
- Add loader field to Service struct
- Remove NewSubject() alias (use S() instead)
- Add tests for new options and NewWithLoader
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>