Bump version to 1.3.1

Patch release: quantized Whisper models (Turbo q5_0 needs ~0.7 GB RAM
instead of ~1.75 GB), a download progress window, and model warm-up at
recording start with a HUD notice when the first transcription is slow.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

macos/WhisperDictate.app/Contents/Info.plist

@@ -19,9 +19,9 @@
 	<key>CFBundlePackageType</key>
 	<string>APPL</string>
 	<key>CFBundleShortVersionString</key>
-	<string>1.3.0</string>
+	<string>1.3.1</string>
 	<key>CFBundleVersion</key>
-	<string>3</string>
+	<string>4</string>
 	<key>LSMinimumSystemVersion</key>
 	<string>13.0</string>
 	<key>LSUIElement</key>