Release v1.4.17 with security fixes, stability hardening and retry improvements

- Fix ZIP path traversal vulnerability (reject entries escaping target dir)
- Add single instance lock (prevent data corruption from multiple instances)
- Add unhandled exception/rejection handlers (prevent silent crashes)
- Fix mainWindow reference cleanup on close
- Add second-instance handler to focus existing window
- Fix claimTargetPath infinite loop (add 10k iteration bound)
- Add duplicate startItem guard (prevent concurrent downloads of same item)
- Clone session in getSnapshot to prevent live-reference mutation bugs
- Clear stateEmitTimer on clearAll to prevent dangling timer emissions
- Add extraction timeout safety (4h deadline with logging)
- Add dedicated unrestrict retry system with longer backoff for Mega-Debrid errors
- Add log rotation (10MB max, keeps one .old backup)
- Fix writeExtractResumeState missing mkdir (prevents crash on deleted dirs)
- Fix saveSessionAsync EXDEV cross-device rename with copy fallback

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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "real-debrid-downloader",
-  "version": "1.4.16",
+  "version": "1.4.17",
   "description": "Real-Debrid Downloader Desktop (Electron + React + TypeScript)",
   "main": "build/main/main/main.js",
   "author": "Sucukdeluxe",