fix: final-review hardening (health route, SSRF edge cases, moonshine names)

feat: add X-ASR + Qwen3-ASR backends, Gemma-4 LLMs; fix review findings

Add speaker name detection feature

Fix Unicode encoding in export headers for Chinese filenames

Fix filename sanitization for Chinese titles in export

Implement document title generation and UI improvements

status in result tab got more informative

add non-tracked

re-implement in FastAPI