feat: Prevent GameServer from restarting after ending by introducin… (#2923)

If this PR fixes an issue, link it below. If not, delete these two
lines.
Resolves #(issue number)
#2919 


In GameManager.tick(), when a game becomes active but hasn't started, a
setTimeout for game.start() is scheduled with a 2-second delay. If the
game finishes or is cancelled within those 2 seconds, game.end() is
called, which clears the existing interval. However:

1.The 2-second timeout still fires. game.start() executes.
2. A NEW setInterval is created for turn execution.
3.Since the game is already ending/finished, it's removed from
GameManager.games, but the interval continues to run forever in the
background


## 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

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

codimo

tests/server/GameLifecycle.test.ts

@@ -0,0 +1,121 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+vi.mock("../../src/core/configuration/ConfigLoader", () => ({
+  getServerConfigFromServer: () => ({
+    otelEnabled: () => false,
+    otelAuthHeader: () => "",
+    otelEndpoint: () => "",
+    env: () => 0, // GameEnv.Dev
+  }),
+  getServerConfig: () => ({
+    otelEnabled: () => false,
+  }),
+}));
+
+vi.mock("../../src/core/Schemas", async () => {
+  const actual = (await vi.importActual("../../src/core/Schemas")) as any;
+  return {
+    ...actual,
+    GameStartInfoSchema: {
+      safeParse: (data: any) => ({ success: true, data: data }),
+    },
+    ServerPrestartMessageSchema: {
+      safeParse: (data: any) => ({ success: true, data: data }),
+    },
+  };
+});
+
+import { GameEnv } from "../../src/core/configuration/Config";
+import { GameType } from "../../src/core/game/Game";
+import { GameServer } from "../../src/server/GameServer";
+
+describe("GameLifecycle", () => {
+  let mockLogger: any;
+  let mockConfig: any;
+
+  beforeEach(() => {
+    vi.useFakeTimers();
+    mockLogger = {
+      child: vi.fn().mockReturnThis(),
+      info: vi.fn(),
+      warn: vi.fn(),
+      error: vi.fn(),
+    };
+    mockConfig = {
+      turnIntervalMs: () => 100,
+      gameCreationRate: () => 1000,
+      env: () => GameEnv.Dev,
+    };
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+    vi.clearAllTimers();
+  });
+
+  it("should not start turn interval if game has ended", async () => {
+    const game = new GameServer(
+      "test-game",
+      mockLogger,
+      Date.now(),
+      mockConfig,
+      { gameType: GameType.Private } as any,
+    );
+
+    // Call end() first - this should set _hasEnded
+    await game.end();
+
+    // Now call start() - this should be a no-op due to our fix
+    game.start();
+
+    // Check if the interval ID is set (it shouldn't be)
+    expect((game as any).endTurnIntervalID).toBeUndefined();
+
+    // Check if _hasStarted remained false (or at least no interval was created)
+    expect(game.hasStarted()).toBe(false);
+  });
+
+  it("should clear turn interval and set _hasEnded on end()", async () => {
+    // We need to initialize the game such that start() can succeed
+    const game = new GameServer(
+      "test-game",
+      mockLogger,
+      Date.now(),
+      mockConfig,
+      {
+        gameType: GameType.Private,
+        gameMap: "plains",
+        gameMapSize: 100,
+      } as any,
+    );
+
+    // Manually trigger prestart to fulfill some internal checks if necessary
+    game.prestart();
+
+    // start() should create the interval
+    game.start();
+    expect((game as any).endTurnIntervalID).toBeDefined();
+
+    // end() should clear it
+    await game.end();
+    expect((game as any).endTurnIntervalID).toBeUndefined();
+    expect((game as any)._hasEnded).toBe(true);
+  });
+
+  it("should be resilient to multiple end() calls", async () => {
+    const game = new GameServer(
+      "test-game",
+      mockLogger,
+      Date.now(),
+      mockConfig,
+      { gameType: GameType.Private } as any,
+    );
+
+    await game.end();
+    expect((game as any)._hasEnded).toBe(true);
+
+    // Should not throw or crash
+    await expect(game.end()).resolves.toBeUndefined();
+    expect((game as any)._hasEnded).toBe(true);
+  });
+});