Add tests for Autopopulate 2.0 jobs system

Comprehensive test suite for the new per-table jobs system:
- JobsTable structure and initialization
- refresh() method with priority and delay
- reserve() method and reservation conflicts
- complete() method with keep option
- error() method and message truncation
- ignore() method
- Status filter properties (pending, reserved, errors, ignored, completed)
- progress() method
- populate() with reserve_jobs=True
- schema.jobs property
- Configuration settings

Author: claude