bug(committor): potential panic in TransactionPreparatorImpl::prepare_for_strategy

[vikions]

Report

What happened:
In magicblock-committor-service/src/transaction_preparator/mod.rs at line 106, there is a .expect() call that can cause a runtime panic in committor workers:

let message = TransactionUtils::assemble_tasks_tx(
    authority,
    &tx_strategy.optimized_tasks,
    self.compute_budget_config.compute_unit_price,
    &lookup_tables,
)
.expect("Possibility to assemble checked above")
.message;

Expected:
Error should be propagated via ? through the existing PreparatorResult error path instead of panicking.

Repro:
The lookup tables passed to the second assemble_tasks_tx call may differ from the first check at line 86, making the assumption in .expect() not strictly guaranteed.

Logs/links:
https://github.com/magicblock-labs/magicblock-validator/blob/master/magicblock-committor-service/src/transaction_preparator/mod.rs#L106

I'd like to work on this fix if no one is assigned yet.

Commit / version

master

Environment

No response