Add Maximum Size for Metrics

[kzscisoft]

Limit metric size to be within 10MB Limit

Issue: #906

Python Version(s) Tested: 3.13

Operating System(s): Ubuntu 25.10

Documentation PR: Issue on Docs repo.

📝 Summary

Modifies the dispatcher classes to allow for additional "hold-back" thresholds to be defined.

🔄 Changes

• simvue.factory has been removed and dispatchers moved to simvue.dispatch.
• A new argument thresholds has been added to the initialiser of all simvue.dispatch classes, this argument is a dictionary allowing you to specify additional thresholds, in this case {"max_size": 10 * 1024 * 1024}.
• The member function add_item now includes a metadata argument where the value for checking against these thresholds is provided: add_item(item, object_type="metrics", ..., metadata=dict(max_size=len(item)).

✔️ Checklist

• Unit and integration tests passing.
• Pre-commit hooks passing.
• Quality checks passing.
• Updated the documentation.