fix: accept media-only messages with empty text in onNewMessage

/./ requires at least one character and silently drops messages with no
text (e.g. Telegram photo/video/file sent without a caption). Switching
to /[\s\S]*/ matches the empty string too, so media-only messages now
reach the router and then the agent.

src/channels/chat-sdk-bridge.ts

@@ -253,12 +253,12 @@ export function createChatSdkBridge(config: ChatSdkBridgeConfig): ChannelAdapter
       // Chat SDK dispatch (handling-events.mdx §"Handler dispatch order") is
       // exclusive: subscribed → onSubscribedMessage; unsubscribed+mention →
       // onNewMention; unsubscribed+pattern-match → onNewMessage. Registering
-      // with `/./` lets the router see every plain message on every
-      // unsubscribed thread the bot can see. The router short-circuits via
+      // with `/[\s\S]*/` lets the router see every plain message (including
+      // media-only messages with empty text) on every unsubscribed thread the
       // getMessagingGroupWithAgentCount (~1 DB read) for unwired channels,
       // so forwarding every one is cheap enough to not need a bridge-side
       // flood gate.
-      chat.onNewMessage(/./, async (thread, message) => {
+      chat.onNewMessage(/[\s\S]*/, async (thread, message) => {
         const channelId = adapter.channelIdFromThreadId(thread.id);
         await setupConfig.onInbound(channelId, thread.id, await messageToInbound(message, false, true));
       });