fix: make result interfaces for ModuleRunnerTransport#invoke more explicit

Author: jay-es

guide/api-environment-runtimes.md

@@ -265,9 +265,7 @@ interface ModuleRunnerTransport {
   connect?(handlers: ModuleRunnerTransportHandlers): Promise<void> | void
   disconnect?(): Promise<void> | void
   send?(data: HotPayload): Promise<void> | void
-  invoke?(
-    data: HotPayload,
-  ): Promise<{ /** result */ r: any } | { /** error */ e: any }>
+  invoke?(data: HotPayload): Promise<{ result: any } | { error: any }>
   timeout?: number
 }
 ```