fix: add OP Stack L1 data fee calculation for smart account

Simulate L1 data fee via simulateOpStackL1Fee for chains with
"op-stack-l1-data-fee" feature and include it in the total estimated fee.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: jungcome7

apps/extension/src/pages/wallet/smart-account/confirm/hooks/use-smart-account-fee.ts

@@ -10,7 +10,7 @@ import { formatFee } from "../../utils";
 
 type FeeState =
   | { status: "loading" }
-  | { status: "success"; gasUsed: number }
+  | { status: "success"; gasUsed: number; l1DataFee?: Dec }
   | { status: "error" };
 
 export function useSmartAccountFee(
@@ -51,6 +51,11 @@ export function useSmartAccountFee(
 
     const ethereumAccount = ethereumAccountStore.getAccount(chainId);
 
+    const modularChainInfo = chainStore.getModularChain(chainId);
+    const hasOpStackFee = modularChainInfo.hasFeature(
+      "op-stack-l1-data-fee"
+    );
+
     ethereumAccount
       .simulateGas(hexAddress, {
         to: hexAddress,
@@ -61,9 +66,25 @@ export function useSmartAccountFee(
           evmChainId
         ),
       })
-      .then((result) => {
+      .then(async (result) => {
+        if (cancelled) return;
+
+        let l1DataFee: Dec | undefined;
+        if (hasOpStackFee) {
+          const l1Fee = await ethereumAccount.simulateOpStackL1Fee({
+            to: hexAddress,
+            value: "0x0",
+            data: "0x",
+          });
+          l1DataFee = new Dec(BigInt(l1Fee));
+        }
+
         if (!cancelled) {
-          setFeeState({ status: "success", gasUsed: result.gasUsed });
+          setFeeState({
+            status: "success",
+            gasUsed: result.gasUsed,
+            l1DataFee,
+          });
         }
       })
       .catch(() => {
@@ -75,6 +96,7 @@ export function useSmartAccountFee(
     };
   }, [
     chainId,
+    chainStore,
     hexAddress,
     evmChainId,
     isValid,
@@ -93,7 +115,10 @@ export function useSmartAccountFee(
     const feePerGas = txFees?.maxFeePerGas ?? txFees?.gasPrice;
     if (!feePerGas || feePerGas.isZero()) return null;
     const gasLimit = Math.ceil(feeState.gasUsed * 1.3);
-    const fee = feePerGas.mul(new Dec(gasLimit)).truncate();
+    let fee = feePerGas.mul(new Dec(gasLimit)).truncate();
+    if (feeState.l1DataFee) {
+      fee = fee.add(feeState.l1DataFee.truncate());
+    }
     return "0x" + BigInt(fee.toString()).toString(16);
   }, [feeState, txFees]);