Implement RedisPendingTransactionStorage #4390
Description
Motivation
We need a robust, shared store for per-user pending transactions in Redis so that multiple relay instances coordinate correctly
Description
Create a new class RedisPendingTransactionStorage that implements PendingTransactionStorage.
Backed by our existing redisClient, it must support:
- getList(address: string): Promise
- addTransaction(address: string, txHash: string): Promise
- removeTransaction(address: string, txHash: string): Promise
- removeAll(): Promise
Use Lua scripts or a Redis transaction to ensure atomic add/remove operations and prevent race conditions.
Add unit tests for each method