Helper type to extract CompiledSubAgent (subagents with runnable) from a DeepAgent.
Uses Extract to filter for subagents that have a runnable property.
InferCompiledSubagents: Extract<InferDeepAgentSubagents<T>[number], __type>const agent = createDeepAgent({ subagents: [subagent1, compiledSubagent] });
type CompiledSubagents = InferCompiledSubagents<typeof agent>;
// Result: the subagent type that has `runnable` property