TypeScript: add extensions to tsconfig and fix type errors (#12781)

* TypeScript: add extensions to tsconfig and fix type errors

- Add extensions/**/* to tsconfig.json includes
- Export ProviderAuthResult, AnyAgentTool from plugin-sdk
- Fix optional chaining for messageActions across channels
- Add missing type imports (MSTeamsConfig, GroupPolicy, etc.)
- Add type annotations for provider auth handlers
- Fix undici/fetch type compatibility in zalo proxy
- Correct ChannelAccountSnapshot property usage
- Add type casts for tool registrations
- Extract usage view styles and types to separate files

* TypeScript: fix optional debug calls and handleAction guards

extensions/discord/src/channel.ts

@@ -31,10 +31,17 @@ import { getDiscordRuntime } from "./runtime.js";
 const meta = getChatChannelMeta("discord");
 
 const discordMessageActions: ChannelMessageActionAdapter = {
-  listActions: (ctx) => getDiscordRuntime().channel.discord.messageActions.listActions(ctx),
-  extractToolSend: (ctx) => getDiscordRuntime().channel.discord.messageActions.extractToolSend(ctx),
-  handleAction: async (ctx) =>
-    await getDiscordRuntime().channel.discord.messageActions.handleAction(ctx),
+  listActions: (ctx) =>
+    getDiscordRuntime().channel.discord.messageActions?.listActions?.(ctx) ?? [],
+  extractToolSend: (ctx) =>
+    getDiscordRuntime().channel.discord.messageActions?.extractToolSend?.(ctx) ?? null,
+  handleAction: async (ctx) => {
+    const ma = getDiscordRuntime().channel.discord.messageActions;
+    if (!ma?.handleAction) {
+      throw new Error("Discord message actions not available");
+    }
+    return ma.handleAction(ctx);
+  },
 };
 
 export const discordPlugin: ChannelPlugin<ResolvedDiscordAccount> = {