Fix websocket data type for room and client storage

Add WsData interface to properly type the websocket data object that
stores room name and client reference. This fixes type errors where
ws.data was previously untyped and causing compilation failures.

src/index.ts

@@ -1,5 +1,10 @@
 import { decode } from "./protocol";
-import { type Client, getOrCreateSession, getSession } from "./session";
+import {
+  type Client,
+  type WsData,
+  getOrCreateSession,
+  getSession,
+} from "./session";
 
 const PORT = Number(process.env.PORT) || 4040;
 
@@ -9,7 +14,7 @@ function isValidRoomName(name: unknown): name is string {
   return /^[a-zA-Z0-9_-]+$/.test(name);
 }
 
-Bun.serve({
+Bun.serve<WsData>({
   port: PORT,
   fetch(req, server) {
     const url = new URL(req.url);

src/session.ts

@@ -2,8 +2,13 @@ import type { ServerWebSocket } from "bun";
 import * as Y from "yjs";
 import { encode } from "./protocol";
 
+export interface WsData {
+  room: string | null;
+  client: Client | null;
+}
+
 export interface Client {
-  ws: ServerWebSocket<{ room: string | null }>;
+  ws: ServerWebSocket<WsData>;
 }
 
 export class Session {