feat: 集成Piper自建TTS并增加朗读回退

speech.js

@@ -1,6 +1,7 @@
 var speechVoices = [];
 var speechVoicesLoaded = false;
 var speechTimer = null;
+var piperFallbackTimer = null;
 
 function refreshSpeechVoices() {
   if (!window.speechSynthesis) return;
@@ -48,10 +49,39 @@ function doSpeak(text, lang) {
 }
 
 function speakText(text, lang) {
-  if (!text || !window.speechSynthesis) return;
+  if (!text) return;
+  if (piperFallbackTimer) clearTimeout(piperFallbackTimer);
+  if (!window.speechSynthesis || !window.SpeechSynthesisUtterance) {
+    playPiperAudio(text, lang);
+    return;
+  }
   refreshSpeechVoices();
   doSpeak(text, lang);
   window.speechSynthesis.getVoices();
+  if (!speechVoicesLoaded) {
+    if (piperFallbackTimer) clearTimeout(piperFallbackTimer);
+    piperFallbackTimer = setTimeout(function() {
+      refreshSpeechVoices();
+      if (!speechVoicesLoaded) playPiperAudio(text, lang);
+    }, 900);
+  }
+}
+
+function playPiperAudio(text, lang) {
+  if (!text) return;
+  fetch('/api/tts', {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ text: text, lang: lang || 'es' })
+  }).then(function(res) {
+    if (!res.ok) throw new Error('tts failed');
+    return res.blob();
+  }).then(function(blob) {
+    var url = URL.createObjectURL(blob);
+    var audio = new Audio(url);
+    audio.onended = function() { URL.revokeObjectURL(url); };
+    audio.play();
+  }).catch(function() {});
 }
 
 function initSpeech() {