[ENH] Add a safety cutoff to the rust log service.

[rescrv]

Description of changes

If a collection on the rust-based log has more than a
configuration-configurable number of records, shut it down hard no
matter what. This happens when compaction gets backlogged. By default,
no more than 1_000_000 can be on the log uncompacted. This is just a
placeholder that we can change.

Test plan

• Tests pass locally with pytest for python, yarn test for js, cargo test for rust

Documentation Changes

N/A

[github-actions]

Reviewer Checklist

Please leverage this checklist to ensure your code review is thorough before approving

Testing, Bugs, Errors, Logs, Documentation

• Can you think of any use case in which the code does not behave as intended? Have they been tested?
• Can you think of any inputs or external events that could break the code? Is user input validated and safe? Have they been tested?
• If appropriate, are there adequate property based tests?
• If appropriate, are there adequate unit tests?
• Should any logging, debugging, tracing information be added or removed?
• Are error messages user-friendly?
• Have all documentation changes needed been made?
• Have all non-obvious changes been commented?

System Compatibility

• Are there any potential impacts on other parts of the system or backward compatibility?
• Does this change intersect with any items on our roadmap, and if so, is there a plan for fitting them together?

Quality

• Is this code of a unexpectedly high quality (Readability, Modularity, Intuitiveness)

[propel-code-bot]

Safety Cutoff Mechanism for Rust Log Service

This PR adds a backpressure mechanism to prevent log service collections from accumulating too many uncompacted records. When a collection exceeds a configurable threshold (default 1,000,000 records), the system rejects further writes to that collection until compaction occurs. This protects the system from memory exhaustion when compaction falls behind.

Key Changes:
• Add backpressure mechanism that rejects writes when collections exceed record threshold
• Introduce configurable num_records_before_backpressure parameter (default: 1,000,000)
• Add backpressure tracking and enforcement in LogServer implementation

Affected Areas:
• Rust log service collection management
• Write operations to collections
• Log service configuration

This summary was automatically generated by @propel-code-bot

[propel-code-bot]

[BestPractice]

Consider using explicit type parameters for HashMap collections. Use of the _ placeholder for type parameters reduces code clarity and can make it harder to understand the data structures being used.

Suggested change

	.collect::<HashMap<_, _>>();
	.collect::<HashMap<CollectionUuid, (Arc<Storage>, Option<Manifest>, Option<Witness>)>>();

⚡ Committable suggestion

Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation.

[HammadB]

We have adopted parking_lot across our codebase.