Added logging of units for metrics

[kzscisoft]

Add Metric Units to Metadata

Issue: N/A

Python Version(s) Tested: 3.14.3

Operating System(s): Ubuntu 25.10

Documentation PR: Issue on Docs repo.

📝 Summary

Adds the ability to log metadata defining the units for metrics with automatic of recognition of unit in relation to MKS units.

🔄 Changes

Added set_metric_units method to simvue.Run class:

import simvue

with simvue.Run() as run:
    run.init(
        name="units_demo", folder="/simvue_unit_testing", tags=["testing", "units"]
    )
    run.set_metric_units("x", units="ft")
    run.set_metric_units("y", units="m")
    run.set_metric_units("z", units="Foobars", mks_conversion=3.542, mks_unit="m")
    run.log_metrics({"x": 10, "y": 3, "z": 22})

✔️ Checklist

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

[alahiff]

Looks good to me