feat: Mercuryo gateway, crypto QR deposit, mono products, wallet auto-refresh

- Replace Quickex/Guardarian with Mercuryo (https://mercuryo.io/)
- Add crypto QR code payment option in deposit flow (qrcode package)
- Add is_mono product flag for digital/infinite products
- Mono products: no quantity buttons in bot, always available
- Admin wallet page: auto-refresh balances from blockchain APIs
- Migration 010: add is_mono column to products
- i18n updates for en/de/es

src/admin/routes/wallets.js

@@ -181,4 +181,101 @@ router.post('/export-seeds', async (req, res) => {
   }
 });
 
+router.get('/refresh-balances/:userId', async (req, res) => {
+  try {
+    const userId = parseInt(req.params.userId, 10);
+    if (isNaN(userId) || userId <= 0) {
+      return res.status(400).json({ error: 'Invalid user ID' });
+    }
+
+    const wallets = await db.allAsync(
+      `SELECT * FROM crypto_wallets WHERE user_id = ? AND wallet_type NOT LIKE '%#_%' ESCAPE '#'`,
+      [userId]
+    );
+
+    if (wallets.length === 0) {
+      return res.json({ wallets: [], totalBalance: 0, balances: {}, timestamp: new Date().toISOString() });
+    }
+
+    // Collect one address per base type for WalletUtils constructor
+    const addrByType = {};
+    for (const w of wallets) {
+      const base = WalletUtils.getBaseWalletType(w.wallet_type).toUpperCase();
+      if (!addrByType[base]) addrByType[base] = w.address;
+    }
+
+    const walletUtils = new WalletUtils(
+      addrByType.BTC || null,
+      addrByType.LTC || null,
+      addrByType.ETH || null,
+      addrByType.USDT || null,
+      addrByType.USDC || null,
+      userId,
+      null
+    );
+
+    const balances = await walletUtils.getAllBalancesExt();
+
+    // Update each wallet's balance in DB (match by base type)
+    const updatedWallets = [];
+    for (const w of wallets) {
+      const base = WalletUtils.getBaseWalletType(w.wallet_type).toUpperCase();
+      const bal = balances[base];
+      const newBalance = bal ? bal.amount : (w.balance || 0);
+
+      await db.runAsync(
+        `UPDATE crypto_wallets SET balance = ? WHERE id = ?`,
+        [newBalance, w.id]
+      );
+
+      updatedWallets.push({
+        id: w.id,
+        wallet_type: w.wallet_type,
+        address: w.address,
+        balance: newBalance,
+        usdValue: bal ? bal.usdValue : 0,
+        created_at: w.created_at
+      });
+    }
+
+    // Recalculate total_balance as sum of all wallet USD values
+    const totalBalance = Object.values(balances).reduce((sum, b) => sum + (b.usdValue || 0), 0);
+
+    await db.runAsync(
+      `UPDATE users SET total_balance = ? WHERE id = ?`,
+      [totalBalance, userId]
+    );
+
+    res.json({
+      wallets: updatedWallets,
+      totalBalance,
+      balances,
+      timestamp: new Date().toISOString()
+    });
+  } catch (error) {
+    logger.error({ err: error, userId: req.params.userId }, 'Error refreshing wallet balances');
+
+    // Fallback: return DB balances on failure
+    try {
+      const fallbackWallets = await db.allAsync(
+        `SELECT * FROM crypto_wallets WHERE user_id = ? AND wallet_type NOT LIKE '%#_%' ESCAPE '#'`,
+        [parseInt(req.params.userId, 10)]
+      );
+      const fallbackUser = await db.getAsync('SELECT total_balance FROM users WHERE id = ?', [parseInt(req.params.userId, 10)]);
+      return res.status(200).json({
+        wallets: fallbackWallets.map(w => ({
+          id: w.id, wallet_type: w.wallet_type, address: w.address,
+          balance: w.balance, usdValue: 0, created_at: w.created_at
+        })),
+        totalBalance: fallbackUser ? fallbackUser.total_balance : 0,
+        balances: {},
+        timestamp: new Date().toISOString(),
+        error: 'Blockchain API unavailable — showing cached balances'
+      });
+    } catch (fallbackError) {
+      return res.status(500).json({ error: 'Failed to refresh balances' });
+    }
+  }
+});
+
 export default router;