fix(chase): detach seed input on scene switch via stage-change subscription

Made-with: Cursor

src/stages/page_chase.ts

@@ -1,4 +1,5 @@
 import { BaseScene } from "@/scene/BaseScene";
+import { sceneManager } from "@/scene/SceneManager";
 import { SceneType } from "@/enums/SceneType";
 import { ChaseGameModel } from "@/game/chase/model";
 import type { Difficulty, NodeId } from "@/game/chase/types";
@@ -41,6 +42,7 @@ export default class ChaseScene extends BaseScene {
   private seedInput = "";
   private difficultyLocked = false;
   private inputAttached = false;
+  private unsubscribeStageChange?: () => void;
 
   constructor(options: ChaseSceneOptions = {}) {
     super("chase", SceneType.Normal);
@@ -96,10 +98,21 @@ export default class ChaseScene extends BaseScene {
   }
 
   protected onSceneEnter(): void {
+    if (!this.unsubscribeStageChange) {
+      this.unsubscribeStageChange = sceneManager.onStageChange((current) => {
+        if (current.name !== this.name) {
+          this.detachSeedInputBridge();
+          return;
+        }
+        this.syncSeedInputBridge();
+      });
+    }
     this.syncSeedInputBridge();
   }
 
   protected onSceneExit(): void {
+    this.unsubscribeStageChange?.();
+    this.unsubscribeStageChange = undefined;
     this.detachSeedInputBridge();
   }
 

tests/stages/page_chase.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, it, vi } from "vitest";
 import ChaseScene from "../../src/stages/page_chase";
 import InitScene from "../../src/stages/page_init";
+import { sceneManager } from "../../src/scene/SceneManager";
 import { Text } from "pixi.js";
 
 function createSceneState() {
@@ -250,4 +251,34 @@ describe("chase stage skeleton", () => {
     scene.update(0, "chase", {} as any);
     expect((scene as any).seedInputElement).toBeUndefined();
   });
+
+  it("detaches seed input immediately on stage change callback", () => {
+    const fakeDocument = createFakeDocument();
+    const getState = vi.fn().mockReturnValue(createSceneState());
+    let stageChangeHandler: ((current: { name: string }) => void) | undefined;
+    let unsubscribed = false;
+    const onStageChangeSpy = vi
+      .spyOn(sceneManager, "onStageChange")
+      .mockImplementation((cb: any) => {
+        stageChangeHandler = cb;
+        return () => {
+          unsubscribed = true;
+        };
+      });
+
+    const scene = new ChaseScene({
+      documentRef: fakeDocument as any,
+      model: { getState, moveThief: vi.fn(), newRound: vi.fn() } as any,
+    });
+    void (scene as any).onSceneLayout();
+    (scene as any).onSceneEnter();
+    expect((scene as any).seedInputElement).toBeTruthy();
+
+    stageChangeHandler?.({ name: "init" });
+    expect((scene as any).seedInputElement).toBeUndefined();
+
+    (scene as any).onSceneExit();
+    expect(unsubscribed).toBe(true);
+    onStageChangeSpy.mockRestore();
+  });
 });