android(call): Increment 2a — native LiveKit call audio, background service, speaker/BT routing

Replaces WebView call media on Android with a native LiveKit connection (iOS
parity), so call audio survives backgrounding and the output can be switched
to Speaker/Bluetooth/Earpiece — the #3 (missing speaker control) and #4
(background audio) items.

Gated behind a new, default-off server flag ANDROID_NATIVE_MEDIA (independent
of ANDROID_CALLS, which only governs the native ring). Flag off = today's
WebView media, video included; flag on = native audio (video is Increment 2b,
so enable it for VOICE testing first). No behavior change until flipped.

Native (mobile/plugins/native-call/android):
- build.gradle: add kotlin-android + io.livekit:livekit-android 2.29.2 (+ twilio
  audioswitch, coroutines) + JitPack repo; minSdk 24 (LiveKit floor).
- CallMedia.kt: LiveKit Room wrapper — connect/mic/disconnect + AudioSwitchHandler
  routing (auto + selectDevice) and route-change events.
- CallForegroundService.java: microphone-type foreground service for background
  audio (no-ops without RECORD_AUDIO so it never crashes the call).
- NativeCallPlugin.java: real bodies for reportOutgoingCall/reconnectRoom/setMuted
  /endCall + new setAudioRoute/getAudioRoute; fires callConnected/callError/audioRoute.
- AndroidManifest: FG service + FOREGROUND_SERVICE(_MICROPHONE)/RECORD_AUDIO/
  MODIFY_AUDIO_SETTINGS/BLUETOOTH_CONNECT.
- android-patch.js: bump the generated app minSdk to 24.

Server:
- config.js/routes.js: ANDROID_NATIVE_MEDIA → /api/meetings/config.androidNativeMedia.

Web (home.html):
- Android flips to the native-media path when androidNativeMedia is set; the
  existing outgoing/answer/mic/end code then drives the plugin unchanged.
- Speaker button wired for Android native: cycles speaker/earpiece/bluetooth via
  NC.setAudioRoute and reflects the real output from the audioRoute event.

Video stays no-op on the native path (Increment 2b).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

server/public/home.html

@@ -4346,11 +4346,19 @@ async function setupNativeCall(){
   const plat=nativePlatform();
   let cfg={}; try{ cfg=await fetch('/api/meetings/config').then(r=>r.json()); }catch(_){}
   if(plat==='android'){
-    // Android Increment 1: native full-screen ring (over the lock screen, wakes from closed via FCM data), but
-    // the WebView still carries the call media. Gated on androidCall (server ANDROID_CALLS=1). The 'android' FCM
+    // Android native calling (ring + answer) gated on androidCall (server ANDROID_CALLS=1). The 'android' FCM
     // token is already registered by setupNativePush — the server call-wake targets it, so no token step here.
     if(!cfg || !cfg.androidCall){ console.log('[nativecall] Android native calling disabled by server — using WebView calls'); return; }
-    _callkitReady=true; _callWebViewMedia=true;
+    _callkitReady=true;
+    // Increment 2: when the server enables native media, the plugin carries the call AUDIO (background audio +
+    // Speaker/Bluetooth) and the WebView must NOT also join SFU media. Until then (default), media stays in the
+    // WebView (video calls included). androidNativeMedia === true → _callWebViewMedia=false (native media path).
+    _callWebViewMedia = !(cfg && cfg.androidNativeMedia);
+    if(!_callWebViewMedia){
+      console.log('[nativecall] Android native call media ON — background audio + native routing');
+      // Android CAN switch the output (unlike iOS): mirror the plugin's real route into the speaker button.
+      try{ NC.addListener('audioRoute', (e)=>{ bzOnAndroidRoute(e); }); }catch(_){}
+    }
   } else {
     // iOS CallKit: native media (the plugin owns this identity's one LiveKit connection). Flipped on once native
     // media carries the audio.
@@ -4385,7 +4393,7 @@ async function setupNativeCall(){
   }catch(e){ console.warn('[nativecall] answerCall failed:', e); } });
   // Enforce the muted-by-default rule against the plugin's actual mic once the room connects (belt-and-braces
   // for builds whose plugin still connects the mic live). meetMic is the source of truth for the mic button.
-  NC.addListener('callConnected', ()=>{ if(meetNative){ try{ NC.setMuted({ muted:!meetMic }); }catch(_){} if(meetCam){ try{ NC.setCamera({ on:true }); }catch(_){} } } }); // re-applies mic/cam after a #12 media reconnect too
+  NC.addListener('callConnected', ()=>{ if(meetNative){ try{ NC.setMuted({ muted:!meetMic }); }catch(_){} if(meetCam){ try{ NC.setCamera({ on:true }); }catch(_){} try{ if(nativeCallAudioOn() && NC.getAudioRoute){ NC.getAudioRoute().then((r)=>bzOnAndroidRoute(r)).catch(()=>{}); } }catch(_){} } }); // re-applies mic/cam (and seeds the Android audio route) after a #12 media reconnect too
   NC.addListener('callError', (e)=>{ console.warn('[callkit] call error:', (e&&e.error)||''); });
   // Muted from the CallKit system UI → reflect it in the meeting window's mic button.
   NC.addListener('setMuted', (e)=>{ if(!e||meetState!=='call'||!meetNative) return; meetMic=!e.muted; try{ updateMicBtn(); setTileMute('__local', !meetMic); meetSend({type:'meeting-state', muted:!meetMic, camOff:!meetCam}); }catch(_){} });
@@ -5588,7 +5596,12 @@ function bzApplyRoute(route){
 }
 // The speaker toggle is usable if the browser supports output switching (setSinkId) OR the native iOS route
 // plugin is present.
-function canRouteAudio(){ try{ if(nativeAudioRoute()) return true; return typeof HTMLMediaElement!=='undefined' && typeof HTMLMediaElement.prototype.setSinkId==='function'; }catch(_){ return false; } }
+function canRouteAudio(){ try{ if(nativeAudioRoute()) return true; if(nativeCallAudioOn()) return true; return typeof HTMLMediaElement!=='undefined' && typeof HTMLMediaElement.prototype.setSinkId==='function'; }catch(_){ return false; } }
+// Android native call media: the NativeCall plugin owns the audio and CAN switch the output (speaker/earpiece/
+// bluetooth), unlike iOS. True only when the server enabled native media and the plugin is present.
+function nativeCallAudioOn(){ try{ return nativePlatform()==='android' && _callkitReady && !_callWebViewMedia && !!nativeCallPlugin(); }catch(_){ return false; } }
+let _androidRoutes=[]; // outputs the plugin reports we can switch to (from the audioRoute event / getAudioRoute)
+function bzOnAndroidRoute(e){ if(!e) return; if(e.output) _nativeOutput=e.output; if(Array.isArray(e.available)) _androidRoutes=e.available; refreshSpkBtn(); }
 // new #4: let the user drag a floating bar out of the way — it otherwise covers part of the shared
 // screen. Drag from anywhere on the bar except a control. Position is remembered per bar.
 function makeDraggable(el, key){
@@ -5637,11 +5650,22 @@ let meetRoute=(()=>{ try{ return localStorage.getItem('bzc_route')||'speaker'; }
 let _nativeOutput=null;
 function iosRoute(){ return _nativeOutput; } // truthy only on iOS native once the plugin has reported
 function spkIcon(){
-  if(iosRoute()){ return _nativeOutput==='bluetooth' ? 'bluetooth' : (_nativeOutput==='wired' ? 'headphones' : 'speaker'); }
+  // iosRoute() is truthy on iOS AND on Android native media (both drive the icon from the real output _nativeOutput).
+  if(iosRoute()){
+    if(_nativeOutput==='bluetooth') return 'bluetooth';
+    if(_nativeOutput==='wired') return 'headphones';
+    if(_nativeOutput==='earpiece') return 'speakerOff'; // Android can route to the earpiece (iOS reports 'receiver')
+    return 'speaker';
+  }
   return meetRoute==='bt' ? 'bluetooth' : (meetRoute==='speaker' ? 'speaker' : 'speakerOff');
 }
 function routeLabel(){
-  if(iosRoute()){ return _nativeOutput==='bluetooth' ? 'Bluetooth' : (_nativeOutput==='wired' ? 'Headset' : 'Speaker'); }
+  if(iosRoute()){
+    if(_nativeOutput==='bluetooth') return 'Bluetooth';
+    if(_nativeOutput==='wired') return 'Headset';
+    if(_nativeOutput==='earpiece') return 'Earpiece';
+    return 'Speaker';
+  }
   return meetRoute==='bt' ? 'Bluetooth / headset' : (meetRoute==='speaker' ? 'Speaker' : 'Earpiece');
 }
 function refreshSpkBtn(){
@@ -5671,7 +5695,7 @@ function bzInitNativeRoute(){
 function bzOnNativeRoute(output){
   if(!output) return;
   _nativeOutput=output;
-  meetRoute = (output==='bluetooth'||output==='wired') ? 'bt' : (output==='speaker' ? 'speaker' : meetRoute);
+  meetRoute = (output==='bluetooth'||output==='wired') ? 'bt' : (output==='earpiece' ? 'earpiece' : (output==='speaker' ? 'speaker' : meetRoute));
   refreshSpkBtn();
 }
 // Detect a connected BT/headset output so the cycle can include it (and the icon can show it).
@@ -5783,6 +5807,19 @@ async function toggleSpeakerphone(){
         : 'On speaker — connect a Bluetooth/wired headset to use it');
     return;
   }
+  // Android native call media: the plugin CAN switch the route — cycle through the outputs it reports (bluetooth/
+  // wired only appear while a headset is connected).
+  if(nativeCallAudioOn()){
+    const NC=nativeCallPlugin(); if(!NC){ return; }
+    const avail=(_androidRoutes && _androidRoutes.length) ? _androidRoutes : ['speaker','earpiece'];
+    const order=['speaker','earpiece','bluetooth','wired'].filter(r=>avail.indexOf(r)>=0);
+    const cur=_nativeOutput||'speaker';
+    const i=order.indexOf(cur);
+    const next=order[(i<0?0:(i+1))%(order.length||1)] || 'speaker';
+    try{ const r=await NC.setAudioRoute({ route: next }); if(r && r.output){ _nativeOutput=r.output; } else { _nativeOutput=next; } }catch(_){ _nativeOutput=next; }
+    refreshSpkBtn(); toast(routeLabel());
+    return;
+  }
   let outs=[]; try{ outs=(await navigator.mediaDevices.enumerateDevices()).filter(x=>x.kind==='audiooutput'); }catch(_){}
   const bt=outs.find(d=>isBtLabel(d.label)); _btConnected=!!bt;
   const routes = ['speaker','earpiece'].concat(bt?['bt']:[]);