fix(electrobun): register message handlers in WebView RPC (was empty, incoming messages ignored)

ui-electrobun/src/mainview/main.ts

@@ -26,8 +26,16 @@ const rpc = Electroview.defineRPC<PtyRPCSchema>({
       // No request handlers needed — Bun only pushes messages to us, not requests.
     },
     messages: {
-      // These are messages that WE send to Bun (fire-and-forget).
-      // Empty: WebView doesn't initiate any fire-and-forget messages.
+      // Messages received FROM Bun (pushed to WebView)
+      "pty.output": (payload: unknown) => payload,
+      "pty.closed": (payload: unknown) => payload,
+      "agent.message": (payload: unknown) => payload,
+      "agent.status": (payload: unknown) => payload,
+      "agent.cost": (payload: unknown) => payload,
+      "remote.event": (payload: unknown) => payload,
+      "remote.statusChange": (payload: unknown) => payload,
+      "btmsg.newMessage": (payload: unknown) => payload,
+      "bttask.changed": (payload: unknown) => payload,
     },
   },
 });