Helper type to extract SubAgent (subagents with middleware) from a DeepAgent.
Uses Extract to filter for subagents that have a middleware property but no runnable.
InferRegularSubagents: Exclude<InferDeepAgentSubagents<T>[number], __type>const agent = createDeepAgent({ subagents: [subagent1, compiledSubagent] });
type RegularSubagents = InferRegularSubagents<typeof agent>;
// Result: the subagent type that has `middleware` property