v0.0.9: feat: add trial plan functionality and related UI updates

- Implemented trial plan creation and editing in the product plans handler.
- Added checks to ensure only one trial plan per product.
- Updated HTML templates to include trial plan options and fields.
- Enhanced JavaScript to dynamically update plan selections based on product choice.
- Introduced trial status indicators in product and plan detail views.
- Added trial-related methods and constants in Go, PHP, and TypeScript SDKs.
- Updated example applications to demonstrate trial license activation and verification.