feat(tests): add Localhost network configuration and enhance gas fee assertions

- Added a new network configuration for the Localhost (chainID: 1337) in `tx-sentinel-networks-map.ts` to support EIP-7702 relay and gasless confirmation tests.
- Updated the gas fee assertions in `gas-fee-tokens-eip-7702-sponsored.spec.ts` to check for the visibility of the Gas Fees Details component and improved timeout settings for better test reliability.

Author: dawnseeker8

tests/api-mocking/mock-responses/tx-sentinel-networks-map.ts

@@ -71,6 +71,28 @@ export const TX_SENTINEL_NETWORKS_MAP = {
     hidden: false,
     sendBundle: false,
   },
+  /**
+   * Local Anvil / fixture chain (0x539). Required for EIP-7702 relay + gasless
+   * confirmation E2E (`gas-fee-tokens-eip-7702-sponsored.spec.ts`): `isRelaySupported`
+   * reads Sentinel `/networks` via `getSentinelNetworkFlags`.
+   */
+  '1337': {
+    name: 'Localhost',
+    group: 'ethereum',
+    chainID: 1337,
+    nativeCurrency: {
+      name: 'ETH',
+      symbol: 'ETH',
+      decimals: 18,
+    },
+    network: 'localhost',
+    explorer: 'http://localhost:8545/explorer',
+    confirmations: true,
+    smartTransactions: true,
+    relayTransactions: true,
+    hidden: false,
+    sendBundle: false,
+  },
   '137': {
     name: 'Polygon Mainnet',
     group: 'polygon',

tests/smoke/confirmations/transactions/gas-fee-tokens-eip-7702-sponsored.spec.ts

@@ -184,9 +184,15 @@ const performSendTransaction = async () => {
   await SendView.pressContinueButton();
   await SendView.inputRecipientAddress(RECIPIENT_ADDRESS_MOCK);
   await SendView.pressReviewButton();
-  await Assertions.expectElementToBeVisible(
-    RowComponents.NetworkFeePaidByMetaMask,
-  );
+  await Assertions.expectElementToBeVisible(RowComponents.GasFeesDetails, {
+    description: 'gas fees row is present on review screen',
+    timeout: 30000,
+  });
+  await Assertions.expectElementToBeVisible(RowComponents.NetworkFeePaidByMetaMask, {
+    description:
+      'network fee shows MetaMask-sponsored gas after relay + simulation settle',
+    timeout: 60000,
+  });
   await Utilities.waitForElementToBeVisible(FooterActions.confirmButton);
   await Utilities.waitForElementToStopMoving(FooterActions.confirmButton, {
     timeout: 5000,