fix: update ServerLobbyChatSchema to use username and isHost fields

- Replace sender (clientID) with username and isHost in schema
- Update tests to match new schema structure
- Fixes TypeScript compilation errors

Author: Phantasm0009

src/core/Schemas.ts

@@ -491,7 +491,8 @@ export const ServerErrorSchema = z.object({
 
 export const ServerLobbyChatSchema = z.object({
   type: z.literal("lobby_chat"),
-  sender: ID,
+  username: z.string(),
+  isHost: z.boolean(),
   text: SafeString.max(300),
 });
 

tests/LobbyChatSchemas.test.ts

@@ -46,16 +46,17 @@ describe("Lobby Chat Schemas", () => {
   test("ServerLobbyChatSchema valid message", () => {
     const msg = ServerLobbyChatSchema.parse({
       type: "lobby_chat",
-      sender: "ABCDEFGH",
+      username: "TestUser",
+      isHost: true,
       text: "Hi host",
     });
-    expect(msg.sender).toBe("ABCDEFGH");
+    expect(msg.username).toBe("TestUser");
+    expect(msg.isHost).toBe(true);
   });
 
-  test("ServerLobbyChatSchema rejects invalid sender id", () => {
+  test("ServerLobbyChatSchema rejects missing fields", () => {
     const result = ServerLobbyChatSchema.safeParse({
       type: "lobby_chat",
-      sender: "BAD-ID", // hyphen invalid for ID regex
       text: "Hi host",
     });
     expect(result.success).toBe(false);