Release v1.4.16 with crash prevention and hang protection

- Add 30s fetch timeouts to ALL API calls (Real-Debrid, BestDebrid, AllDebrid, Mega-Web)
- Fix race condition in concurrent worker indexing (runWithConcurrency)
- Guard JSON.parse in RealDebrid response with try-catch
- Add try-catch to fs.mkdirSync in download pipeline (handles permission denied)
- Convert MD5/SHA1 hashing to streaming (prevents OOM on large files)
- Add error handling for hash manifest file reading
- Prevent infinite hangs on unresponsive API endpoints

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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "real-debrid-downloader",
-  "version": "1.4.15",
+  "version": "1.4.16",
   "description": "Real-Debrid Downloader Desktop (Electron + React + TypeScript)",
   "main": "build/main/main/main.js",
   "author": "Sucukdeluxe",