frontend: add missing feetarget types

Since the BitBoxApp uses mempool.space as default fee estimator,
these types were missing.

Commit that introduced mempool.space fee estimator:
- bd52d93

Author: thisconnect

frontends/web/src/api/account.ts

@@ -1,5 +1,5 @@
 /**
- * Copyright 2021-2024 Shift Crypto AG
+ * Copyright 2021-2025 Shift Crypto AG
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -364,7 +364,7 @@ export const sendTx = (
   return apiPost(`account/${code}/sendtx`, txNote);
 };
 
-export type FeeTargetCode = 'custom' | 'low' | 'economy' | 'normal' | 'high';
+export type FeeTargetCode = 'custom' | 'low' | 'economy' | 'normal' | 'high' | 'mHour' | 'mHalfHour' | 'mFastest';
 
 export interface IProposeTxData {
     address?: string;