Fix WS recv race + session recycle 20 with async overlap + Modal deploy

Fix WS recv race + session recycle 20 with async overlap

Sync backend with LN-TTS: fix Chapter 1 scraper bug, add sentence offsets, improve error handling, update README

Sentence-chunked WS audio with smoothing

Fix audio jitter: remove real-time sleep, add ms_start to sentence events

Improve chapter parsing, add sentence_total and voice to chapter_info

Fix CMD: replace complex inline shell with start.sh script

Add .gitignore to exclude pycache, models, venv

Sync backend features: novel_details, realtime flag, portable PORT, Azure deploy docs

Add Space homepage and runtime info endpoints

Deploy existing backend in Docker Space on port 7860

initial commit