feat(l2): enhance monitor performance

[gianbelinche]

Motivation
If a sequencer runs for a long time, it stops, and we run it again activating the monitor, it takes a long time to start and is slow.

Description
Makes the monitor load and work faster by simplifying the batches processing.

How to Test

• Run a Sequencer (I suggest make restart in crates/l2).
• Run the prover with make init-prover in crates/l2.
• Let the sequencer ran for some time (at least 60 batches)
• Kill the sequencer
• Add --monitor to the init-l2-no-metrics target in crates/l2/Makefile.
• Run make init-l2-no-metrics

[Copilot]

Pull Request Overview

This PR enhances monitor performance by optimizing how batches are processed and refreshed. The changes focus on reducing redundant database queries and improving startup time when restarting a sequencer with monitor enabled after it has been running for an extended period.

• Optimizes batch refresh logic to only fetch incomplete batches instead of all batches
• Limits the number of batches fetched by introducing a 50-batch window from the latest batch
• Refactors batch processing into smaller, more focused functions for better maintainability

Comments suppressed due to low confidence (1)

crates/l2/monitor/widget/batches.rs:146

• This is another instance where a type alias for the batch tuple would improve maintainability and reduce code duplication of clippy suppressions.

    #[expect(clippy::type_complexity)]

[github-actions]

Lines of code report

Total lines added: 24
Total lines removed: 0
Total lines changed: 24

Detailed view

+--------------------------------------------+-------+------+
| File                                       | Lines | Diff |
+--------------------------------------------+-------+------+
| ethrex/crates/l2/monitor/widget/batches.rs | 188   | +22  |
+--------------------------------------------+-------+------+
| ethrex/crates/l2/sequencer/errors.rs       | 326   | +2   |
+--------------------------------------------+-------+------+