Save in-progress game history when the app is quit mid-session

[Copilot]

Quitting the app mid-game silently discarded the current session's progress because the game plugin's stop() method (which persists via the score service) was never called.

Approach

Intercept before-quit in the main process, ask the renderer to flush progress via IPC, then exit once confirmed — with a 5-second force-exit fallback.

Changes

• main.js — before-quit now calls event.preventDefault(), sends app:before-quit to the renderer window, and starts a QUIT_TIMEOUT_MS (5s) watchdog. A new app:quit-ready IPC handler calls app.exit(0) once the renderer signals completion.

• app/preload.js — Exposes a new receive(channel, callback) bridge method backed by ipcRenderer.once() (allowlist: app:before-quit); adds app:quit-ready to the invoke allowlist.

• app/interface.js — Tracks the active plugin in activePlugin. Registers an app:before-quit handler during DOMContentLoaded that awaits activePlugin.stop(), then invokes app:quit-ready. Plugin reference is set on game load and cleared on return to the main menu.

// interface.js — quit handler (simplified)
window.api.receive('app:before-quit', async () => {
  if (activePlugin && typeof activePlugin.stop === 'function') {
    await activePlugin.stop();   // persists score via scoreService
  }
  await window.api.invoke('app:quit-ready');
});

• Tests — preload.test.js covers receive() allowlist and ipcRenderer.once wiring; interface.test.js adds 5 cases for the quit handler (active game, no game, stop throws, after return-to-menu).