fix: AquesTalk truncates speech on space - use 、 as word separator

Root cause: AquesTalk_Synthe silently drops all text after a space.
English segments previously joined with spaces (word gap), so anything
after the first space was silent. Replace all spaces with 、 (Japanese
comma pause) which AquesTalk supports natively.

- PUNCT_MAP maps space -> 、
- convertEnglishSegment joins words with 、
- synthesize collapses consecutive pauses, strips residual spaces

Verified: 'Actually这个proposal是非常creative的' WAV 19316 -> 79196 bytes

tts_bridge.js

@@ -192,6 +192,7 @@ function spellWord(word) {
 const PUNCT_MAP = {
   ",": "、", ".": "。", "!": "！", "?": "？",
   "，": "、", "。": "。", "！": "！", "？": "？",
+  " ": "、", // AquesTalk truncates on space; use 、 pause instead
 };
 
 function wordToKana(word) {
@@ -227,7 +228,7 @@ function convertEnglishSegment(text) {
 
   for (const token of words) {
     if (/^\s+$/.test(token)) {
-      parts.push(" "); // keep word gap for AquesTalk pause
+      parts.push("、"); // word gap: AquesTalk truncates on space, use 、 instead
       continue;
     }
     if (PUNCT_MAP[token] !== undefined) {
@@ -237,7 +238,7 @@ function convertEnglishSegment(text) {
     parts.push(wordToKana(token));
   }
 
-  return parts.join("").replace(/ +/g, " ");
+  return parts.join("").replace(/、+/g, "、");
 }
 
 function synthesize(kanaText) {
@@ -265,6 +266,9 @@ function synthesize(kanaText) {
     result += convertEnglishSegment(englishBuf);
   }
 
+  // Collapse consecutive pauses; strip any residual spaces (AquesTalk truncates on space)
+  result = result.replace(/ +/g, "、").replace(/、+/g, "、").replace(/^、|、$/g, "");
+
   console.error(`[bridge] SYNTH IN:  ${trimmed}`);
   console.error(`[bridge] SYNTH OUT: ${result}`);