feat(plugins): sync plugin commands to Telegram menu and export gateway types

- Add plugin command specs to Telegram setMyCommands for autocomplete
- Export GatewayRequestHandler types in plugin-sdk for plugin authors
- Enables plugins to register gateway methods and appear in command menus

src/plugin-sdk/index.ts

@@ -63,6 +63,11 @@ export type {
   ClawdbotPluginService,
   ClawdbotPluginServiceContext,
 } from "../plugins/types.js";
+export type {
+  GatewayRequestHandler,
+  GatewayRequestHandlerOptions,
+  RespondFn,
+} from "../gateway/server-methods/types.js";
 export type { PluginRuntime } from "../plugins/runtime/types.js";
 export { normalizePluginHttpPath } from "../plugins/http-path.js";
 export { registerPluginHttpRoute } from "../plugins/http-registry.js";