Gotcha Core

Lightweight schema core for the Gotcha web framework.

This crate holds the [Schematic] trait, the [EnhancedSchema] type, and the Schematic implementations for common data types. It intentionally depends only on schema-related crates (no axum/tokio/tower), so a crate that only needs to derive and use Schematic can depend on gotcha_core directly without pulling in the whole web framework.

The heavyweight gotcha crate re-exports everything here, so existing use gotcha::Schematic; code keeps working unchanged.