fix: harden the Electron 43 release runtime

Upgrade Electron, electron-builder, and electron-updater to patched versions, align the supported Node.js toolchain, and preserve secure file drops through the context-isolated webUtils bridge.

Cover the Electron 43 file-path migration with a real temporary-file drag-and-drop regression test and retain zero-vulnerability lockfile resolution.

src/renderer-globals.d.ts

@@ -336,6 +336,7 @@ interface ApiBridge {
     selectFolder(): Promise<string | null>;
     selectVideoFile(): Promise<string | null>;
     selectMultipleVideos(): Promise<string[] | null>;
+    getPathForFile(file: File): string;
     saveVideoDialog(defaultName: string): Promise<string | null>;
     openFolder(path: string): Promise<void>;
     openFile(path: string): Promise<boolean>;