Parakeet model verification and auto-download

- Check model folder for required files (vocab.txt, encoder, decoder)
- Download from Hugging Face when model missing
- Auto-download on app start if path set but folder empty
- Download button and progress in Settings UI

Made-with: Cursor

README.md

@@ -47,7 +47,7 @@ Default hotkey: **Ctrl+Shift+D** (hold = record, release = transcribe + paste)
 | **Hotkey** | Global Push-to-Talk (e.g. Ctrl+Shift+D) |
 | **Input source** | Companion app or microphone |
 | **parakeet-cli path** | Empty = in PATH (default: parakeet-cli) |
-| **Model path** | Empty = default path (platform-dependent) |
+| **Model path** | Empty = default path. If folder is empty or invalid, use "Download model" to fetch from Hugging Face |
 | **Paste method** | Auto | Keyboard buffer | Clipboard |
 
 **Storage location:** `%LOCALAPPDATA%\HotKeet\settings.json` (Windows) or `~/.config/HotKeet/settings.json` (Linux/macOS)