help: add nginx+dual-PHP, prepend mechanism, hidden tab WS nuances
https://github.com/golnet1/majordomo-piper_tts/com...

piper_tts.js: close WS on visibilitychange (background tabs)

• WS disconnect on document.hidden, reconnect on visible
• replaces windowActive/tryPlay/localStorage approach
• background tabs no longer receive TTS events at all

install/uninstall: align with Vosk on modules/prepend.php

• install: create shared modules/prepend.php loader if missing
• install: clean up old direct Piper .htaccess line
• install: add auto_prepend_file for modules/prepend.php
• uninstall: check if Vosk is still installed before removing
  shared loader and .htaccess line
• prepend.php: add cache buster via filemtime
  https://github.com/golnet1/majordomo-piper_tts/com...

piper_tts.js: windowActive flag with proper focus target check + localStorage token lock
https://github.com/golnet1/majordomo-piper_tts/com...

help: clarify prepend.php troubleshooting, make section collapsible
https://github.com/golnet1/majordomo-piper_tts/com...

Bootstrap styling: settings and models templates
https://github.com/golnet1/majordomo-piper_tts/com...

prepend: inject script only if not in frame (window.top===window.self)
https://github.com/golnet1/majordomo-piper_tts/com...

cleanup: remove dead code and fix stale references

• Removed unused language constants PIPER_TTS_PLAYER_SETUP,
  PIPER_TTS_AUTO_SETUP, PIPER_TTS_SPA_SETUP from both ru/en files
• Removed dead handlers install_start, install_progress (replaced by install_model)
• Removed creation of unused /tmp/piper-tts directory in install()
• Fixed help.html voice list to match actual 5 voices
• Fixed help.html cache dir default path to match code
• Fixed WS_PORT not being passed to JS (added window.PIPER_WS_PORT
  in piper_tts.html)
  https://github.com/golnet1/majordomo-piper_tts/com...

fix: check prepend.php exists before adding .htaccess entry; prevent system crash on install
https://github.com/golnet1/majordomo-piper_tts/com...