Convert NikeAMoments to artifact_processor (structured moments table)

[abrignoni]

Summary

NikeAMoments was old-style. It rendered a redundant activities table plus a custom interactive JS timeline of per-run moments. The activities table is already covered (more richly) by the existing Nike - Activities artifact, and the JS timeline can't render in LAVA — so the moment data was effectively unqueryable.

This converts it to a single @artifact_processor that emits Nike - Activity Moments: one row per activity_moment (Activity ID, Timestamp, Moment Type, Value, Description).

Changes

• Removed ArtifactHtmlReport + the interactive timeline JS (add_timeline/add_timeline_script).
• Dropped the redundant runs table (covered by Nike - Activities).
• New Nike - Activity Moments table surfaces moment data that was previously only visible inside the JS widget.
• Description reproduces the original timeline labels (Run paused/resumed, Split KM/Mile, GPS signal lost/found).
• More complete than the original: unknown moment types are kept with a blank description instead of being silently dropped.
• Aware UTC datetimes via a per-file _ms_to_utc; helpers/style match NikeActivities.py.

Validation

• ast.parse OK; 0 old-style refs (ArtifactHtmlReport/report./add_timeline/tsv/timeline).
• Reserved-word audit: header set creates a SQLite table cleanly.
• pylint (CI config): 10.00/10.
• PluginLoader loads cleanly (total 538).
• Functional smoke test on a synthetic fixture: all 7 moment-type branches produce the correct descriptions; unknown type preserved.