Command-line interface for the dengjen-tts speech synthesis engine.
Builds the `dengjen` binary. `dengjen speak <config|voice-key>` reads text from a file or stdin, synthesizes it with a chosen model config in Lazy, Parallel, Batched, or Realtime mode, and writes the resulting audio to a file or stdout.
`dengjen voices list|install|remove|refresh` manages Piper voices; see the usage guide. `dengjen <config>` was replaced by `dengjen speak <config>`.