Phase 2: Constraint Validation - 2 plans in 1 wave (parallel) - Both plans autonomous (no checkpoints) Plan 02-01: Migrate 13 XCTest tests to Swift Testing Plan 02-02: Add edge case tests and document constraint API Note: ItineraryConstraints is already fully implemented. This phase verifies and standardizes tests. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>