//! Request identity — **OSS (Enlil) core.**
//!
//! This is deliberately minimal and dependency-free so the open-source `enlil`
//! binary can attribute a request to a caller without pulling in the proprietary
//! multi-tenant auth stack (`middleware::auth`), which owns JWT validation,
//! API-key lookup, admin authorization and the tenant registry.
//!
//! In OSS single-tenant mode this is populated with a default identity; in the
//! cloud build it is populated by `middleware::auth::auth_middleware` from a
//! proxy key, `x-tenant-id` header, or a signed JWT.
//!
//! `middleware::auth` re-exports `TenantContext` from here, so existing call
//! sites keep working unchanged (see DEVELOPMENT_PLAN.md, Step 2).
/// Identifies the caller a request is attributed to.
///
/// Carried in Axum request extensions.