audio.cpp TTS engines (2026-09-06, upstream main b0757573: IndexTTS-2.5 + Higgs Audio v3 + Fish S2 Pro + FireRedTTS3)

audio.cpp composite build (index_tts2,higgs_audio_tts,fish_audio,fireredtts3) for SubtitleEdit's IndexTTS-2.5 engine.

Source: 0xShug0/audio.cpp @ b0757573c90bf3ada5cf8ffbc69f3ab80a7a6947, Apache-2.0.
Binaries only — IndexTTS-2.5 weights are downloaded from Hugging Face at runtime and carry the separate bilibili Model Use License.

See SHA256SUMS.txt for the hashes to add to DownloadHashManager.