Update plan-refactor-tests.md to reflect completed phases

Mark all Phase 2 and Phase 3 tasks as complete. Update to reflect:
- Actual Angular form field names (name not title for salary range)
- Removed fields (department description, salary range currency)
- Corrected RBAC behavior (Manager can create salary ranges/positions)
- Key patterns established (Material dialog delete, focus+blur validation,
  role switch logout, numeric input try-catch)
- Updated POM Quick Reference with correct method names
- Phase 4 final results with all bug-fix commits recorded

Author: workcontrolgit