feat: Enhance the request interface to include all required properties and methods

[3m1n3nc3]

This PR ensures the Request interface provides a full-featured, developer-friendly API similar to Laravel’s request helper, while maintaining H3ravel’s TypeScript-first design.

• All standard properties (method, url, query, body, headers, params) are available.
• Helper methods like input(), only(), and wantsJson() work as expected.
• Types are explicit and developer-friendly.
• Tests cover at least 90% of the new functionality.

Closes #71