-- test/plugins_agent/spawn_test.lua-- Exercises agent.new()/:submit()/:free() for test_lua_agent.c. clm.tool_register("spawn_test", {    description = "spawn a subagent and submit one prompt to it",    no_prompt = true,    params_schema = { type = "object", properties = {} },    invoke = function(args, ctx)        local child = agent.new({ max_iterations = 1 })        local text, err = child:submit("say hi")        child:free()        if err then            ctx:fail("child error: " .. tostring(err))        else            ctx:complete("child said: " .. tostring(text))        end    end,})