feat: add StealthEX deposit integration for wallet top-up

- New depositHandler.js: wallet selection, amount picker, instruction page with StealthEX link
- Updated topUpHandler.js: shows deposit buttons per wallet + deposit via StealthEX
- Routes: deposit_select_wallet, deposit_wallet_, deposit_amount_, deposit_copy_
- Config: STEALTHEX_REF env var for optional referral
- Fixed archived wallets filter in deposit wallet query

.env.example

@@ -29,6 +29,10 @@ COMMISSION_WALLET_USDT=
 COMMISSION_WALLET_USDC=
 COMMISSION_WALLET_ETH=
 
+# --- StealthEX Deposit Integration ---
+# Optional: your StealthEX referral ID (leave empty if none)
+STEALTHEX_REF=
+
 # --- WireGuard ---
 WG_ENABLED=false
 WG_PRIVATE_KEY=