fix: use Hono Bun WebSocket pattern (export default fetch+websocket)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/server/src/index.ts

@@ -2,7 +2,7 @@ import { env } from "@haushaltsApp/env/server";
 import { Hono } from "hono";
 import { cors } from "hono/cors";
 import { logger } from "hono/logger";
-import { websocket } from "./ws/bun-ws";
+import { websocket } from "hono/bun";
 import { registerRoutes } from "./routes";
 
 const app = new Hono();
@@ -20,13 +20,7 @@ app.use(
 
 registerRoutes(app);
 
-if (typeof Bun !== "undefined" && !process.env.BUN_TEST) {
-  Bun.serve({
-    port: Number(process.env.PORT ?? 3000),
-    hostname: "0.0.0.0",
-    fetch: app.fetch,
-    websocket,
-  });
-}
-
-export default app;
+export default {
+  fetch: app.fetch,
+  websocket,
+};