fix: Register IPC handlers only once to avoid blank window

[nekketsuuu]

This will fix the issue where only a blank window is displayed when the window is closed and reopened.

createWindow() re-registered ipcMain.handle("getConfig") on every call, so the second call threw "Attempted to register a second handler" and skipped win.loadURL(), leaving a blank window. Register the handlers once per process and resolve the target window from the sender.

A screenshot of the blank window:

[Copilot]

🟡 Changes recommended

The updated showUpdateQueryDialog flow is still async while the renderer uses ipcRenderer.sendSync, which can return undefined or deadlock unless the main handler is made synchronous (or both sides are migrated to invoke/handle).

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

This PR fixes an Electron main-process lifecycle issue where closing and reopening the window could result in a blank window due to IPC handlers being re-registered on each createWindow() call.

Changes:

• Refactors IPC registration into a one-time registerIpcHandlers() guarded by a module-level flag.
• Updates IPC listeners to resolve the target BrowserWindow from event.sender rather than capturing a specific win instance.

File summaries

File	Description
src/main/window.ts	Registers IPC handlers once per process and resolves the originating window per IPC event to avoid duplicate handler errors and blank-window loads.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 1
• Review effort level: Lite

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[Copilot]

🟢 Approval recommended

The change directly addresses duplicate IPC registration while preserving multi-window behavior.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 0 new
• Review effort level: Balanced

[morishin]

Thanks!