feat: add external import with MD5 deduplication and drive detection

- Import from folder or removable drive via File menu
- MD5 checksum-based duplicate detection from audio content
- Windows drive detection with removable/fixed type labels
- Drive accessibility verification before listing
- Import files copied to _Imports/<date>/ folders
- Comprehensive logging for import debugging

package.json

@@ -1,6 +1,6 @@
 {
   "name": "audio-sort",
-  "version": "0.4.0",
+  "version": "0.5.0",
   "description": "Electron audio sorting application with fuzzy search, tagging, library management, and advanced waveform editing with audio splitting capabilities for WAV files.",
   "author": "litruv",
   "main": "dist/main/main/index.js",