Private Lobbies: Add kick player functionality (#1436)

## Description:
Added player management features so lobby hosts can kick players from
private games. This includes both UI changes and backend work.

### What's new:
- Hosts can now kick players from private lobbies with a simple button
- Added host badges and remove buttons to the UI
- Made sure only hosts can kick people, and hosts can't kick themselves

### How it works:
- When someone creates a private game, they automatically become the
host
- Kicking happens through WebSocket "kick-player" events
- Server checks that you're actually the host before letting you kick
anyone

<img width="1291" height="871" alt="Screenshot 2025-07-15 002114"
src="https://github.com/user-attachments/assets/ea575f83-a0f4-45d1-9cfe-7521d373f3d5"
/>



### Known Issues:
- Kicked player gets general message (same when kicked for multi tab)

### Other Issues:
- Host abandoment still existent (host clicks on x; or is closing tab)

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I have read and accepted the CLA agreement (only required once).

## Please put your Discord username so you can be contacted if a bug or
regression is found:

[UN]nvm

---------

Co-authored-by: floriankilian <floriankilian@users.noreply.github.com>

src/server/GameManager.ts

@@ -28,20 +28,31 @@ export class GameManager {
     return false;
   }
 
-  createGame(id: GameID, gameConfig: GameConfig | undefined) {
-    const game = new GameServer(id, this.log, Date.now(), this.config, {
-      gameMap: GameMapType.World,
-      gameType: GameType.Private,
-      difficulty: Difficulty.Medium,
-      disableNPCs: false,
-      infiniteGold: false,
-      infiniteTroops: false,
-      instantBuild: false,
-      gameMode: GameMode.FFA,
-      bots: 400,
-      disabledUnits: [],
-      ...gameConfig,
-    });
+  createGame(
+    id: GameID,
+    gameConfig: GameConfig | undefined,
+    creatorClientID?: string,
+  ) {
+    const game = new GameServer(
+      id,
+      this.log,
+      Date.now(),
+      this.config,
+      {
+        gameMap: GameMapType.World,
+        gameType: GameType.Private,
+        difficulty: Difficulty.Medium,
+        disableNPCs: false,
+        infiniteGold: false,
+        infiniteTroops: false,
+        instantBuild: false,
+        gameMode: GameMode.FFA,
+        bots: 400,
+        disabledUnits: [],
+        ...gameConfig,
+      },
+      creatorClientID,
+    );
     this.games.set(id, game);
     return game;
   }

src/server/GameServer.ts

@@ -41,7 +41,7 @@ export class GameServer {
   private turns: Turn[] = [];
   private intents: Intent[] = [];
   public activeClients: Client[] = [];
-  // Used for record record keeping
+  private LobbyCreatorID: string | undefined;
   private allClients: Map<ClientID, Client> = new Map();
   private clientsDisconnectedStatus: Map<ClientID, boolean> = new Map();
   private _hasStarted = false;
@@ -71,8 +71,10 @@ export class GameServer {
     public readonly createdAt: number,
     private config: ServerConfig,
     public gameConfig: GameConfig,
+    lobbyCreatorID?: string,
   ) {
     this.log = log_.child({ gameID: id });
+    this.LobbyCreatorID = lobbyCreatorID ?? undefined;
   }
 
   public updateGameConfig(gameConfig: Partial<GameConfig>): void {
@@ -118,6 +120,13 @@ export class GameServer {
       });
       return;
     }
+    // Log when lobby creator joins private game
+    if (client.clientID === this.LobbyCreatorID) {
+      this.log.info("Lobby creator joined", {
+        gameID: this.id,
+        creatorID: this.LobbyCreatorID,
+      });
+    }
     this.log.info("client (re)joining game", {
       clientID: client.clientID,
       persistentID: client.persistentID,
@@ -223,6 +232,42 @@ export class GameServer {
               );
               return;
             }
+
+            // Handle kick_player intent via WebSocket
+            if (clientMsg.intent.type === "kick_player") {
+              const authenticatedClientID = client.clientID;
+
+              // Check if the authenticated client is the lobby creator
+              if (authenticatedClientID !== this.LobbyCreatorID) {
+                this.log.warn(`Only lobby creator can kick players`, {
+                  clientID: authenticatedClientID,
+                  creatorID: this.LobbyCreatorID,
+                  target: clientMsg.intent.target,
+                  gameID: this.id,
+                });
+                return;
+              }
+
+              // Don't allow lobby creator to kick themselves
+              if (authenticatedClientID === clientMsg.intent.target) {
+                this.log.warn(`Cannot kick yourself`, {
+                  clientID: authenticatedClientID,
+                });
+                return;
+              }
+
+              // Log and execute the kick
+              this.log.info(`Lobby creator initiated kick of player`, {
+                creatorID: authenticatedClientID,
+                target: clientMsg.intent.target,
+                gameID: this.id,
+                kickMethod: "websocket",
+              });
+
+              this.kickClient(clientMsg.intent.target);
+              return;
+            }
+
             this.addIntent(clientMsg.intent);
           }
           if (clientMsg.type === "ping") {
@@ -453,6 +498,10 @@ export class GameServer {
     }
   }
 
+  public isPrivateLobbyCreator(clientID: string): boolean {
+    return this.LobbyCreatorID === clientID;
+  }
+
   phase(): GamePhase {
     const now = Date.now();
     const alive: Client[] = [];

src/server/Worker.ts

@@ -15,6 +15,7 @@ import {
   ClientMessageSchema,
   GameRecord,
   GameRecordSchema,
+  ID,
   ServerErrorMessage,
 } from "../core/Schemas";
 import { CreateGameInputSchema, GameInputSchema } from "../core/WorkerSchemas";
@@ -90,6 +91,13 @@ export function startWorker() {
     "/api/create_game/:id",
     gatekeeper.httpHandler(LimiterType.Post, async (req, res) => {
       const id = req.params.id;
+      const creatorClientID = (() => {
+        if (typeof req.query.creatorClientID !== "string") return undefined;
+
+        const trimmed = req.query.creatorClientID.trim();
+        return ID.safeParse(trimmed).success ? trimmed : undefined;
+      })();
+
       if (!id) {
         log.warn(`cannot create game, id not found`);
         return res.status(400).json({ error: "Game ID is required" });
@@ -122,10 +130,11 @@ export function startWorker() {
         return res.status(400).json({ error: "Worker, game id mismatch" });
       }
 
-      const game = gm.createGame(id, gc);
+      // Pass creatorClientID to createGame
+      const game = gm.createGame(id, gc, creatorClientID);
 
       log.info(
-        `Worker ${workerId}: IP ${ipAnonymize(clientIP)} creating game ${game.isPublic() ? "Public" : "Private"} with id ${id}`,
+        `Worker ${workerId}: IP ${ipAnonymize(clientIP)} creating ${game.isPublic() ? "Public" : "Private"}${gc?.gameMode ? ` ${gc.gameMode}` : ""} game with id ${id}${creatorClientID ? `, creator: ${creatorClientID}` : ""}`,
       );
       res.json(game.gameInfo());
     }),