OptionalcontextAn HttpError's context: sent for a 4xx, or with includeStack.
OptionaldetailsA validation's details (which fields failed and why).
OptionalheadersHeaders the response carries: Allow for a 405, WWW-Authenticate for a 401.
What the client may read: the message of an HttpError, a Hono
HTTPException or an error marked expose; for anything else the
status text (Internal Server Error), unless includeStack is on.
OptionalrequestThe request's id, when RequestIdFeature set one.
OptionalstackOnly with includeStack.
An error as the response contract sees it: what the client is told and with which status. The Kernel builds one for every error (thrown, a 404, a failed validation, a feature's refusal) and the contract turns it into the body.