Audit and fix 52 test correctness issues across 22 files

Systematic audit of 1,191 tests found tests written to pass rather than
verify correctness. Key fixes:

Infrastructure:
- TestClock: fixed timezone from .current to America/New_York (deterministic)
- TestFixtures: added 1.3x road routing factor to match production
- ItineraryTestHelpers: real per-city coordinates instead of hardcoded (40,-80)

Planning tests:
- Added missing Scenario E factory dispatch tests
- Tightened 12 loose assertions (>= 1 → == 8.0, > 0 → range checks)
- Fixed 4 no-op tests that accepted both success and failure
- Fixed wrong repeat-city invariant (was checking same-day, not different-day)
- Fixed tautological assertion in missing-stadium edge case

Services/Domain/Export tests:
- Replaced 4 placeholder tests (#expect(true)) with real assertions
- Fixed tautological assertions in POISearchServiceTests
- Fixed Chicago coordinate in RegionMapSelectorTests (-89 → -87.6553)
- Added sort order verification to ItineraryRowFlatteningTests

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

SportsTimeTests/Planning/TravelSegmentIntegrityTests.swift

@@ -533,7 +533,7 @@ struct TravelIntegrity_EdgeCaseTests {
         let result = ItineraryBuilder.build(stops: stops, constraints: .default)
         #expect(result != nil, "Same-city stops should build")
         #expect(result!.travelSegments.count == 1, "Must still have segment")
-        // Distance should be very small (same coords)
+        #expect(result!.travelSegments[0].estimatedDistanceMiles < 1, "Same-city distance should be near zero")
     }
 
     @Test("Cross-country trip (NYC→LA) rejected with 1 driver, feasible with 2")