fix(ai-chat): re-derive thread titles on decryption so encrypted chats do not stick on the fallback

src/app/features/bots/useBotConversations.ts

@@ -1,5 +1,5 @@
 import { useEffect, useMemo, useState } from 'react';
-import { MsgType, Room, ThreadEvent } from 'matrix-js-sdk';
+import { MatrixEvent, MatrixEventEvent, MsgType, Room, ThreadEvent } from 'matrix-js-sdk';
 import { trimReplyFromBody } from '../../utils/room';
 import { useMatrixClient } from '../../hooks/useMatrixClient';
 
@@ -65,12 +65,23 @@ export const useBotConversations = (room: Room): BotConversation[] => {
     // (which fired an extra bump per reply plus one for every unrelated main-timeline event).
     room.on(ThreadEvent.New, bump);
     room.on(ThreadEvent.Update, bump);
+
+    // In an encrypted DM a thread root can decrypt AFTER its last ThreadEvent.Update
+    // (e.g. the bot's reply lands before the root is decrypted); without this the title
+    // stays stuck on the localized fallback until the next reply. The client re-emits
+    // Decrypted for every event, so re-derive when one lands in this room.
+    const onDecrypted = (event: MatrixEvent) => {
+      if (event.getRoomId() === room.roomId) bump();
+    };
+    mx.on(MatrixEventEvent.Decrypted, onDecrypted);
+
     return () => {
       cancelled = true;
       room.off(ThreadEvent.New, bump);
       room.off(ThreadEvent.Update, bump);
+      mx.off(MatrixEventEvent.Decrypted, onDecrypted);
     };
-  }, [room]);
+  }, [room, mx]);
 
   return useMemo(() => {
     const conversations = room