The HTTP wire DTOs and their engine-result -> DTO mappings move from
omnigraph-server's api module into a new omnigraph-api-types crate that
both server and CLI can depend on (engine must not — DAG: api-types ->
engine, never the reverse). The crate holds plain serde/utoipa types only;
the transport-coupled error->status mapping stays in the server (lib.rs/
handlers). The one server-runtime coupling (query_catalog_entry, which
maps a StoredQuery — not a wire type) stays behind in api.rs, now calling
the crate's pub param_descriptor.
api.rs becomes a thin `pub use omnigraph_api_types::*` re-export, so every
omnigraph_server::api::Foo path (handlers, the OpenApi schema list, CLI
imports) resolves unchanged. openapi.json regenerates BYTE-IDENTICAL (the
Phase-2 referee: 77 openapi tests green, zero diff).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
