Validate network supports ENS before resolution attempt

ENS resolution was attempted on any network including BSC and opBNB,
where the ENS registry contract does not exist. This caused cryptic
contract call errors instead of a clear message.

- Added network allowlist check before ENS resolution
- Supports Ethereum mainnet, Sepolia, and Goerli by name or chain ID
- Returns clear error message when ENS is used on unsupported networks

Author: mefai-dev

src/evm/services/ens.ts

@@ -20,6 +20,11 @@ export async function resolveAddress(
 
   // If it looks like an ENS name (contains a dot), try to resolve it
   if (addressOrEns.includes(".")) {
+    const ensNetworks = ['ethereum', 'sepolia', 'goerli', '1', '11155111', '5'];
+    if (!ensNetworks.includes(String(network).toLowerCase())) {
+      throw new Error(`ENS resolution is only supported on Ethereum networks. Current: ${network}`);
+    }
+
     try {
       // Normalize the ENS name first
       const normalizedEns = normalize(addressOrEns)