fix: clean chat navigation — edit messages instead of sending new ones

All callback handlers now use editOrSendCallback() to edit the existing
message in-place instead of bot.sendMessage() which creates new messages
and clutters the chat. If edit fails (message too old), the old message
is deleted and a new one sent.

Added src/utils/messageUtils.js with:
- editOrSendCallback(callbackQuery, text, options) — edit or fallback
- editOrSend(chatId, messageId, text, options) — edit or fallback
- deleteAndSend(chatId, messageId, text, options) — delete then send

Fixed handlers:
- userProductHandler: handleBuyProduct errors, handlePay validation/stock errors
- userPurchaseHandler: viewPurchase errors, handleConfirmReceived errors, handlePurchaseListPage errors
- userLocationHandler: all error paths now edit in-place
- userDeletionHandler: both error paths now edit in-place
- wallet/balanceHandler: showBalance error (text command, acceptable)
- wallet/refreshHandler: user not found and refresh errors
- wallet/topUpHandler: wallet loading error
- wallet/createHandler: invalid wallet type error
- wallet/historyHandler: both transaction history error paths
- wallet/archiveHandler: archived wallets error

src/utils/messageUtils.js

@@ -0,0 +1,31 @@
+import bot from '../context/bot.js';
+
+export async function editOrSend(chatId, messageId, text, options = {}) {
+    if (messageId) {
+        try {
+            const result = await bot.editMessageText(text, {
+                chat_id: chatId,
+                message_id: messageId,
+                ...options,
+            });
+            return result;
+        } catch (e) {
+            // message too old or already edited — delete and send new
+            try { await bot.deleteMessage(chatId, messageId); } catch (_) {}
+        }
+    }
+    return bot.sendMessage(chatId, text, options);
+}
+
+export async function editOrSendCallback(callbackQuery, text, options = {}) {
+    const chatId = callbackQuery.message.chat.id;
+    const messageId = callbackQuery.message.message_id;
+    return editOrSend(chatId, messageId, text, options);
+}
+
+export async function deleteAndSend(chatId, messageId, text, options = {}) {
+    if (messageId) {
+        try { await bot.deleteMessage(chatId, messageId); } catch (_) {}
+    }
+    return bot.sendMessage(chatId, text, options);
+}