Disk space pre-check, nested extraction, lower I/O priority for hybrid extraction

- Add disk space check before extraction (aborts if insufficient space)
- Add single-level nested archive extraction (archives inside archives)
- Blacklist .iso/.img/.bin/.dmg from nested extraction
- Set real Windows I/O priority (Very Low) on UnRAR via NtSetInformationProcess
- Reduce UnRAR threads to -mt1 during hybrid extraction
- Fix double episode renaming (s01e01e02 pattern)

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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "real-debrid-downloader",
-  "version": "1.5.37",
+  "version": "1.5.38",
   "description": "Real-Debrid Downloader Desktop (Electron + React + TypeScript)",
   "main": "build/main/main/main.js",
   "author": "Sucukdeluxe",