Whisper Input v1.3.19

Fixes Windows Right Alt hotkey handling in both dictation triggering and shortcut recording. The Windows low-level hook now normalizes generic extended Alt events to AltRight/RightAlt, and the shortcut recorder waits for native recording mode before accepting key input. Adds the missing hotkey regression test entrypoint and extends Windows hotkey tests for generic extended Alt. Also allows the packaging script to clean the fixed sibling app artifacts directory safely.