Make prewarm actually prewarm account

[stevenlanders]

• before running load, this will send a tx for each account in the pool at a rate of 100 tps
• then we can run load without worrying about the warm-up state of the chain

2025/09/26 20:01:39 🔥 Prewarming progress: 4300 accounts processed...
2025/09/26 20:01:40 🔥 Prewarming progress: 4400 accounts processed...
2025/09/26 20:01:41 🔥 Prewarming progress: 4500 accounts processed...
2025/09/26 20:01:42 🔥 Prewarming progress: 4600 accounts processed...
2025/09/26 20:01:43 🔥 Prewarming progress: 4700 accounts processed...
2025/09/26 20:01:44 🔥 Prewarming progress: 4800 accounts processed...
2025/09/26 20:01:45 🔥 Prewarming progress: 4900 accounts processed...
2025/09/26 20:01:46 🔥 Prewarming progress: 5000 accounts processed...
2025/09/26 20:01:46 🔥 Prewarming complete! Processed 5000 accounts

Includes some settings that we don't need to override unless we're doing something interesting (like prewarm tps and worker settings)