stage #4599 onto master (v0.51.555) — add id-ID Edge TTS voice + fix Listen button playing-state (parity)

latipun7: adds id-ID-GadisNeural to the Edge TTS allowlist (Edge TTS is a core builtin -> parity, default-in)
+ picker label + sets speaking-state at start of _playEdgeTtsChunked so the Listen button reflects playback.
Co-authored-by: latipun7 <latipun7@users.noreply.github.com>

api/routes.py

@@ -13577,6 +13577,7 @@ def _handle_tts(handler, parsed):
         "fr-CA-AntoineNeural", "fr-CA-JeanNeural",
         "fr-CA-SylvieNeural", "fr-CA-ThierryNeural",
         "fr-FR-DeniseNeural", "fr-FR-EloiseNeural", "fr-FR-HenriNeural",
+        "id-ID-GadisNeural",
     }
     if voice not in allowed:
         from api.helpers import bad as _bad

static/panels.js

@@ -7372,6 +7372,7 @@ async function loadSettingsPanel(){
           {value:'zh-CN-YunyangNeural',label:'Yunyang (Chinese, Male)'},
           {value:'en-US-AriaNeural',label:'Aria (English, Female)'},
           {value:'en-US-GuyNeural',label:'Guy (English, Male)'},
+          {value:'id-ID-GadisNeural',label:'Gadis (Indonesian, Female)'},
         ];
         ttsVoiceSel.innerHTML='<option value="">Default (Xiaoxiao)</option>';
         edgeVoices.forEach(v=>{

static/ui.js

@@ -6095,6 +6095,8 @@ function _buildBrowserUtterance(text, btn){
 }
 
 function _playEdgeTtsChunked(text, btn){
+  _ttsSpeaking=true;
+  if(btn) btn.dataset.speaking='1';
   const chunks=_splitForTTS(text);
   const _playOne=function(idx){
     if(idx>=chunks.length){