feat(w3): ship v1.4.0 export matrix, cockpit tasks, and focus ambient

Add ExportMatrixService for txt/md/docx/pdf, extend ExportModal, cockpit outline tasks, focus ambient sound, and E2E-PDF-01 with 134 passing unit tests.

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

src/main/ipc/handlers/export-matrix.handler.ts

@@ -0,0 +1,18 @@
+import { ipcMain } from 'electron'
+import { IPC } from '../../../shared/ipc-channels'
+import type { ExportMatrixParams } from '../../../shared/export-matrix'
+import { ExportMatrixService } from '../../services/export-matrix.service'
+import type { BookRegistryService } from '../../services/book-registry'
+import type { GlobalSettingsService } from '../../services/global-settings'
+import { wrap } from '../result'
+
+export function registerExportMatrixHandlers(
+  registry: BookRegistryService,
+  settings: GlobalSettingsService
+): void {
+  const svc = new ExportMatrixService(registry, settings)
+
+  ipcMain.handle(IPC.EXPORT_MATRIX_EXPORT, (_e, params: ExportMatrixParams) =>
+    wrap(() => svc.pickAndExport(params))
+  )
+}