Add configuration models for the new schedule-based pipeline configuration:
- ScheduleConfig: Per-schedule configuration (Enabled, IntervalMinutes, PrePurge, ReIndex, UpdateWhen)
- ScheduleDefaults: Default configurations for Mass (weekly), Daily, and Hourly schedules
- PipelineSchedules: Per-pipeline schedule overrides
- MergeWith method for merging pipeline overrides with defaults
Part of Task 1 from pipeline-schedule-alignment implementation plan.
Joseph Doherty