Fix extraction failure on long paths (>260 chars) with \?\ prefix

Add longPathForWindows() helper that prefixes extract target directories
with \?\ on Windows, bypassing the 260-char MAX_PATH limit. Applied to
both WinRAR/UnRAR and 7z arguments. Fixes "Die Syntax für den
Dateinamen, Verzeichnisnamen" errors when archive internal directories
create deeply nested output paths.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "real-debrid-downloader",
-  "version": "1.5.15",
+  "version": "1.5.16",
   "description": "Real-Debrid Downloader Desktop (Electron + React + TypeScript)",
   "main": "build/main/main/main.js",
   "author": "Sucukdeluxe",