# Feature Doc Entity
### Scope
- **Purpose**: Collect navigational hubs linking all artifacts for each user-facing trait-checking capability.
- **Responsibility**: Index of feature doc instances for the implements crate.
- **In Scope**: User-facing capabilities of the implements crate.
- **Out of Scope**: API contracts (→ api/), correctness invariants (→ invariant/), internal implementation.
### Overview Table
| 001 | [Trait Implementation Check](001_trait_implementation_check.md) | Non-consuming runtime check whether a type implements a trait | ✅ |