tts: purge cached audio and dequeue on message delete

When a message is deleted, drop its cached TTS audio (keys `${messageId}-${voice}`),
remove any pending entries from the playback queue, and if it is the message
currently playing, stop it and advance the queue. Track currentQueuedMessageId
so the active item can be identified. Keeps auto-play sequencing correct and
prevents a deleted message's stale audio from replaying.

templates/chat.html

@@ -143,6 +143,7 @@ const dompurify_config = {
 let userHasScrolledUp = false;
 let currentAudio = null; // To keep track of the currently playing audio
 let currentQueuedAudio = null; // To keep track of currently playing queued TTS audio
+let currentQueuedMessageId = null; // messageId of the queued audio currently playing (for cleanup on delete)
 let audioCache = {}; // Cache to store audio blobs
 
 // Flag to prevent mutual updates on desktop/mobile
@@ -1240,8 +1241,9 @@ function processNextTTS() {
     
     isPlayingTTS = true;
     const { text, playButton, messageId } = ttsQueue.shift();
+    currentQueuedMessageId = messageId;
     console.log("Processing TTS from queue:", messageId);
-    
+
     // Use non-blocking async processing
     speakTextQueued(text, playButton, messageId)
         .then(() => {
@@ -1252,6 +1254,7 @@ function processNextTTS() {
         })
         .finally(() => {
             isPlayingTTS = false;
+            currentQueuedMessageId = null;
             // Schedule next item with minimal delay to prevent blocking
             setTimeout(processNextTTS, 10);
         });
@@ -1331,8 +1334,9 @@ function toggleAutoPlayTTS() {
             currentQueuedAudio.currentTime = 0;
             currentQueuedAudio = null;
         }
+        currentQueuedMessageId = null;
     }
-    
+
     updateAutoPlayTTSDisplay();
 }
 
@@ -1804,6 +1808,30 @@ socket.on("message_deleted", (data) => {
     if (messageElement) {
         messageElement.remove();
     }
+
+    // Drop cached TTS audio for this message (keys are `${messageId}-${voice}`).
+    // The trailing dash keeps "12-" from matching "120-...".
+    const cachePrefix = data.message_id + "-";
+    Object.keys(audioCache).forEach((key) => {
+        if (key.startsWith(cachePrefix)) {
+            delete audioCache[key];
+        }
+    });
+
+    // Remove any pending queue entries for this message so the rest play in order.
+    ttsQueue = ttsQueue.filter((item) => item.messageId != data.message_id);
+
+    // If it's the message currently playing, stop it and advance the queue.
+    if (currentQueuedMessageId != null && currentQueuedMessageId == data.message_id) {
+        if (currentQueuedAudio) {
+            currentQueuedAudio.pause();
+            currentQueuedAudio.currentTime = 0;
+            currentQueuedAudio = null;
+        }
+        currentQueuedMessageId = null;
+        isPlayingTTS = false;
+        setTimeout(processNextTTS, 10);
+    }
 });
 
 // Socket event for when a message is updated