The implemented IAnalytics refined the signature ADR-024 sketched:
events are attributed to the user set by identify() (the standard SDK
model) rather than passed per track() call, the attribute parameter is
named `attributes` consistently, and AnalyticsUser stays id-only with
traits riding identify()'s second argument. The code is the more
idiomatic contract and docs/guides/analytics.md already matched it —
update the ADR's interface block, manifest example, and PII-boundary
section to describe what shipped.