It lets a test drive ctx.subagents and the model-facing dsh-tool-subagent through the real Cordis loader/export path, exercising provider registration, async start, start-time capability validation, required-signal cancellation, result, dispose, and structured output deterministically and keylessly.

Usage

Load it as a plugin (functional shape: name/inject/Config/apply, no default). Config (all optional):

Key	Default	Meaning
`name`	`mock`	Registry name to register the provider under.
`reply`	`mock subagent reply`	The scripted child's final answer text.
`stopReason`	`completed`	The stop reason `result` settles with.
`capabilities`	all `true`	Which start-time capabilities (`outputSchema`, `depthLimit`, `toolFilter`, and `persona`) the provider advertises.
`inheritsParentContext`	`false`	Conversation-history descriptor: `false` means fresh, while `true` exercises seeded/fork wording. It says nothing about tool, service, scope, or authority inheritance.
`structured`	`{ reply }`	Structured value surfaced when a request carries an `outputSchema` and the capability is on.

Aborting the required request signal or disposing before result settles flips the stop reason to aborted, so both holder-facing cancellation paths are observable.