fix(telegram): preserve messageThreadId for DM reply threads

Previously, resolvedThreadId was always used for delivery, but
resolveTelegramForumThreadId() returns undefined for non-forum chats.
This caused DM reply threads to lose their thread context, sending
replies to the main chat instead of the thread.

Now we use messageThreadId directly for DM chats, while keeping
resolvedThreadId for forum groups where topic resolution is needed.

src/telegram/bot-message-context.ts

@@ -656,7 +656,8 @@ export const buildTelegramMessageContext = async ({
     msg,
     chatId,
     isGroup,
-    resolvedThreadId,
+    // For DM reply threads use messageThreadId; for forum groups use resolvedThreadId
+    resolvedThreadId: isGroup ? resolvedThreadId : messageThreadId,
     isForum,
     historyKey,
     historyLimit,