Add Phase, CurrentJobType, IdleSleepSeconds, IterationStartedAt,
LastIterationEndedAt, and LastIterationWorkDetected to SchedulerStatus.
Set SchedulerTickSeconds to match IdleSleepSeconds for backward
compatibility.
Add MaxJobTypeDurationSeconds to SchedulerJobTypeStatus and remove
NextDetectionAt and DetectionIntervalSeconds.
Update GetSchedulerStatus to read iteration tracking fields and
adapt waiting status logic for the new model.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>