refactor: route channel runtime via plugin api

extensions/whatsapp/index.ts

@@ -1,12 +1,14 @@
 import type { ClawdbotPluginApi } from "clawdbot/plugin-sdk";
 
 import { whatsappPlugin } from "./src/channel.js";
+import { setWhatsAppRuntime } from "./src/runtime.js";
 
 const plugin = {
   id: "whatsapp",
   name: "WhatsApp",
   description: "WhatsApp channel plugin",
   register(api: ClawdbotPluginApi) {
+    setWhatsAppRuntime(api.runtime);
     api.registerChannel({ plugin: whatsappPlugin });
   },
 };