add fix to the voice language

fix: espeak env

update default highlight color

add espeak handler to cli for now (#19)

* add espeak handler

* add progress dialog and show downloading in terminal

* feat: add progress bar support for espeak download in PiperTTS

* feat: add espeak data check and download in generate_piper_raw_speech methods

* refactor: move generate_piper_raw_speech_with_progress from Language to VoiceManager

* small improvments

* refactor: simplify espeak installation and runtime handling in voice manager

refactor: improve espeak download progress tracking in voice manager

refactor: simplify let_and_return in espeak_handler download logic

update version in cargo toml

add release files