feat(w2): add PackService for .novel and .novel-all export/import

Introduce pack-bootstrap chunk, ZipArchive-based PackService with progress IPC,
book registry import helpers, and IT-PACK-01 / IT-ALL-02 integration tests.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/main/index.ts

@@ -51,9 +51,11 @@ function createWindow(): void {  mainWindow = new BrowserWindow({
 }
 
 app.whenReady().then(async () => {
-  const { books } = registerIpc()
+  const { books, settings } = registerIpc()
   const { bootstrapImportHandlers } = await import('./import-bootstrap.js')
   bootstrapImportHandlers(books)
+  const { bootstrapPackHandlers } = await import('./pack-bootstrap.js')
+  bootstrapPackHandlers(books, settings)
 
   ipcMain.handle(IPC.WINDOW_MINIMIZE, (event) => {
     BrowserWindow.fromWebContents(event.sender)?.minimize()