v2.0.9 — Cascade AO router + meeting diarization ASR backends: - New 'cascade' backend (Stage AO): Whisper-AI primary + GigaAM fallback per-call when avg_logprob ≤ -0.20. Eliminates Whisper subtitle-credit hallucinations. Bench: 9.43% WER vs 10.16% Whisper-alone (-0.73 pp). - Restore 'large-v3-turbo-russian' (Stage AI fine-tune). - GigaAM model selector restored. Progressive transcription: - VAD-aligned 10s window with 1.5s update cadence + honest gating. - Eliminates mid-word window cuts and silence hallucinations. Streaming dedup: - Levenshtein + partial-match (≥80% words + first-word anchor) + substring search for shifted overlaps. Catches Whisper's morphological vacillation (упало↔упала) and one-word substitutions (рак↔рот) in overlap regions. Stage N retranscribe: - Re-transcribes each pyannote turn from pre-amped audio for clean punctuation/capitalisation. Pre-turn gates drop wrong-language and low-confidence turns. Language correction: - Majority-vote at finalize only re-flips LOW-confidence (lang_prob<0.5) outliers — preserves high-confidence EN code-switching segments. Hot-reload safety: - Backend/model swap now respawns process silently — works around CTranslate2 CUDA-context abort on hot-reload. Docs: - New docs/guides/CASCADE_AO_MODE.md with meeting/interview use cases. - README + README_ru updated for 5 backends + diarization.