564bd47132
Extends the existing Clock with the metrics a host needs to gate
time-sensitive data against the equipment's sync state (E148 §6.3):
offset_seconds() current applied offset vs system clock
last_drift_seconds() signed drift observed at the most recent sync
sync_count() how many successful syncs have happened
sync_quality() Synchronized (|drift|<=1s) /
Drifting (<=60s) / Unsynchronized (>60s or
never synced)
The thresholds are tuneable per call; the defaults match typical fab
practice but the application can pass tighter bounds for tracelog-
sensitive flows. set_time_string() now snapshots the apparent delta
between the previously-applied offset and the new one as
last_drift_seconds_ at the moment of resync; no background timer.
Three new test cases cover the initial Unsynchronized state, a large
forward drift registering as Unsynchronized, and a same-value resync
landing as Synchronized.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>