refactor: migrate messaging plugins to sdk

src/channels/plugins/load.ts

@@ -1,36 +1,25 @@
 import type { ChannelId, ChannelPlugin } from "./types.js";
-import type { ChatChannelId } from "../registry.js";
+import type { PluginRegistry } from "../../plugins/registry.js";
 import { getActivePluginRegistry } from "../../plugins/runtime.js";
 
-type PluginLoader = () => Promise<ChannelPlugin>;
-
-// Channel docking: load *one* plugin on-demand.
-//
-// This avoids importing `src/channels/plugins/index.ts` (intentionally heavy)
-// from shared flows like outbound delivery / followup routing.
-const LOADERS: Record<ChatChannelId, PluginLoader> = {
-  telegram: async () => (await import("./telegram.js")).telegramPlugin,
-  whatsapp: async () => (await import("./whatsapp.js")).whatsappPlugin,
-  discord: async () => (await import("./discord.js")).discordPlugin,
-  slack: async () => (await import("./slack.js")).slackPlugin,
-  signal: async () => (await import("./signal.js")).signalPlugin,
-  imessage: async () => (await import("./imessage.js")).imessagePlugin,
-};
-
 const cache = new Map<ChannelId, ChannelPlugin>();
+let lastRegistry: PluginRegistry | null = null;
+
+function ensureCacheForRegistry(registry: PluginRegistry | null) {
+  if (registry === lastRegistry) return;
+  cache.clear();
+  lastRegistry = registry;
+}
 
 export async function loadChannelPlugin(id: ChannelId): Promise<ChannelPlugin | undefined> {
+  const registry = getActivePluginRegistry();
+  ensureCacheForRegistry(registry);
   const cached = cache.get(id);
   if (cached) return cached;
-  const registry = getActivePluginRegistry();
   const pluginEntry = registry?.channels.find((entry) => entry.plugin.id === id);
   if (pluginEntry) {
     cache.set(id, pluginEntry.plugin);
     return pluginEntry.plugin;
   }
-  const loader = LOADERS[id as ChatChannelId];
-  if (!loader) return undefined;
-  const plugin = await loader();
-  cache.set(id, plugin);
-  return plugin;
+  return undefined;
 }