Carry usage freshness into notification observations so current service status
can still be processed without clearing or priming quota, pace, and reset
baselines from obsolete measurements in a successful CLI response.

Add failing-then-passing regressions for repeated warnings, missed resets,
first observations, and live incident handling through the real cache adapter.

Documentation impact: update the data freshness and development guides and
Unreleased changelog. TODO's CLI/parity inventory and configuration, metadata,
translations, and README behavior summaries remain unchanged.