Let streamers name their AI assistant; fix overlay TTS audio overlap

Streamer dashboard gains an editable AI assistant name (default
"Альтушка Ирина"), stored per-streamer and used for the overlay label,
TTS intro, and DeepSeek system prompt. Also fixes a bug where a long
message's TTS audio could still be playing when the next queued
message started its own audio — the overlay queue now waits for the
current audio to actually finish (not just the configured display
duration) before advancing.

server.js

@@ -16,6 +16,7 @@ const {
   getViewerName,
   setViewerName,
   updateDisplayDuration,
+  updateAiName,
 } = require('./db');
 const { censorText } = require('./profanity');
 
@@ -125,6 +126,7 @@ app.get('/api/dashboard', requireAuth, (req, res) => {
     senderUrl: `${origin}/s/${streamer.sender_token}`,
     ttsVoice: streamer.tts_voice,
     displayDurationSeconds: streamer.display_duration_seconds,
+    aiName: streamer.ai_name,
   });
 });
 
@@ -141,8 +143,16 @@ app.post('/api/settings', requireAuth, (req, res) => {
   if (!Number.isInteger(seconds) || seconds < 1 || seconds > 120) {
     return res.status(400).json({ error: 'displayDurationSeconds must be an integer between 1 and 120' });
   }
-
   updateDisplayDuration(streamer.id, seconds);
+
+  if (typeof req.body.aiName === 'string') {
+    const aiName = req.body.aiName.trim().slice(0, 60);
+    if (!aiName) {
+      return res.status(400).json({ error: 'aiName must not be empty' });
+    }
+    updateAiName(streamer.id, aiName);
+  }
+
   res.json({ displayDurationSeconds: seconds });
 });
 
@@ -156,6 +166,14 @@ app.get('/api/viewer-name', requireAuth, (req, res) => {
   res.json({ name });
 });
 
+app.get('/api/streamer-info', (req, res) => {
+  const streamer = findStreamerBySenderToken(req.query.token);
+  if (!streamer) {
+    return res.status(404).json({ error: 'unknown link' });
+  }
+  res.json({ aiName: streamer.ai_name });
+});
+
 app.get('/overlay/:token', (req, res) => {
   res.sendFile(path.join(__dirname, 'public', 'overlay.html'));
 });
@@ -199,16 +217,17 @@ function broadcastMessage(room, id, text, from, durationMs, ttsText, voice) {
     });
 }
 
-function getAiSystemPrompt() {
+function getAiSystemPrompt(aiName) {
+  let basePrompt;
   try {
-    const content = fs.readFileSync(AI_PROMPT_PATH, 'utf8').trim();
-    return content || FALLBACK_AI_PROMPT;
+    basePrompt = fs.readFileSync(AI_PROMPT_PATH, 'utf8').trim() || FALLBACK_AI_PROMPT;
   } catch {
-    return FALLBACK_AI_PROMPT;
+    basePrompt = FALLBACK_AI_PROMPT;
   }
+  return `Тебя зовут ${aiName}. ${basePrompt}`;
 }
 
-async function getAiReply(text) {
+async function getAiReply(text, aiName) {
   const res = await fetch('https://api.deepseek.com/chat/completions', {
     method: 'POST',
     headers: {
@@ -218,7 +237,7 @@ async function getAiReply(text) {
     body: JSON.stringify({
       model: 'deepseek-chat',
       messages: [
-        { role: 'system', content: getAiSystemPrompt() },
+        { role: 'system', content: getAiSystemPrompt(aiName) },
         { role: 'user', content: text },
       ],
       max_tokens: 150,
@@ -295,18 +314,19 @@ io.on('connection', (socket) => {
       };
 
       if (aiReply && DEEPSEEK_API_KEY) {
+        const aiName = streamer.ai_name || 'Альтушка Ирина';
         // Wait for the AI reply text before showing anything, so the viewer's
         // message and the AI reply land in the overlay queue back-to-back
         // instead of the reply trailing in later with an awkward gap.
-        getAiReply(message)
+        getAiReply(message, aiName)
           .then((replyText) => {
             broadcastOriginal();
 
             const aiMessageId = crypto.randomUUID();
             console.log(`[ai] streamer=${streamer.id} id=${aiMessageId} reply="${replyText}"`);
             broadcastMessage(
-              room, aiMessageId, replyText, 'Альтушка Ирина 🤖', durationMs,
-              `Альтушка Ирина отвечает. ${replyText}`,
+              room, aiMessageId, replyText, `${aiName} 🤖`, durationMs,
+              `${aiName} отвечает. ${replyText}`,
               AI_VOICE
             );
           })