Expose aggregated metrics

[flora-hofmann-frequenz]

Example:MetricSample(timestamp=datetime.datetime(2025, 7, 8, 9, 10, 20, tzinfo=datetime.timezone.utc), microgrid_id=13, component_id=262, metric='BATTERY_SOC_PCT_avg', value=43.198001861572266),
MetricSample(timestamp=datetime.datetime(2025, 7, 8, 9, 10, 20, tzinfo=datetime.timezone.utc), microgrid_id=13, component_id=262, metric='BATTERY_SOC_PCT_min', value=42.70000076293945),
MetricSample(timestamp=datetime.datetime(2025, 7, 8, 9, 10, 20, tzinfo=datetime.timezone.utc), microgrid_id=13, component_id=262, metric='BATTERY_SOC_PCT_max', value=43.29999923706055),

[Copilot]

Pull Request Overview

Updates the metric sample iterator to also expose aggregated metrics and documents this new capability.

• Adds handling for aggregated_metric (avg, min, max, raw values) in __iter__.
• Removes the old math.nan fallback for missing simple metrics.
• Updates release notes to mention the new feature.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/frequenz/client/reporting/_types.py	Expanded __iter__ to support aggregated_metric variants and dropped the NaN fallback.
RELEASE_NOTES.md	Added a bullet noting that aggregated metrics are now exposed.

Comments suppressed due to low confidence (3)

src/frequenz/client/reporting/_types.py:104

• Add unit tests covering the new aggregated metric logic (avg, min, max, raw values) to verify correct iteration behavior and catch future regressions.

                if sample.value.HasField("aggregated_metric"):

RELEASE_NOTES.md:13

• [nitpick] For consistency with the surrounding list style, replace the leading * with - in this bullet point.

* Expose aggregated metrics if available.

src/frequenz/client/reporting/_types.py:104

• [nitpick] Use elif instead of a second if when checking for aggregated_metric to ensure exclusive handling and avoid evaluating both branches if both fields were ever present.

                if sample.value.HasField("aggregated_metric"):