Fix audio, routing, auth, and stream lifecycle

- Switch OBS output to RTMP; add FFmpeg AAC->Opus transcoding via MediaMTX
  runOnReady so WebRTC can carry audio (WebRTC requires Opus, not AAC)
- Enable RTSP on localhost so FFmpeg reads game path without publisher conflict;
  viewers connect to game-opus path (H264+Opus)
- Fix WHEP/HLS path prefix stripping in NPM advanced config; move all custom
  locations (/whep, /hls, /v3) out of NPM GUI and into advanced conf so
  trailing-slash proxy_pass correctly strips prefixes before hitting MediaMTX
- Fix MediaMTX API port 49997->19997 (49997 was in Windows ephemeral range)
- Add /status proxy endpoint to OBS HTTP server so frontend can poll stream
  readiness without hitting /v3/ through NPM where auth_request blocked it
- Fix authInternalUsers: split publish (localhost only) from read (any IP)
  so WHEP viewers are not challenged with Basic Auth by MediaMTX
- Remove muted attribute from video element; show unmute/play button on
  autoplay block so viewers get audio after one click
- Fix webrtcAdditionalHosts to include LAN IP 192.168.50.254
- Fix hlsAllowOrigin->hlsAllowOrigins deprecation warning
- Move MediaMTX/HTTP server startup to script_load (not streaming started)
  so MediaMTX is ready before OBS attempts RTMP connection
- Log MediaMTX output to bin/mediamtx.log for easier debugging

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/js/player.js

@@ -16,8 +16,8 @@
  */
 
 (function () {
-    const WHEP_URL = '/whep/game/whep';
-    const HLS_URL = '/hls/game/index.m3u8';
+    const WHEP_URL = '/whep/game-opus/whep';
+    const HLS_URL = '/hls/game-opus/index.m3u8';
     const HLS_JS_CDN = 'https://cdn.jsdelivr.net/npm/hls.js@1.5.17/dist/hls.min.js';
     const WHEP_TIMEOUT_MS = 10000;
     const RECONNECT_DELAY_MS = 3000;