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/ItineraryBuilderTests.swift

@@ -60,8 +60,8 @@ struct ItineraryBuilderTests {
         #expect(result != nil)
         #expect(result?.stops.count == 2)
         #expect(result?.travelSegments.count == 1)
-        #expect(result?.totalDrivingHours ?? 0 > 0)
-        #expect(result?.totalDistanceMiles ?? 0 > 0)
+        #expect((3.0...6.0).contains(result?.totalDrivingHours ?? 0), "NYC→Boston should be 3-6 hours driving")
+        #expect((200...400).contains(result?.totalDistanceMiles ?? 0), "NYC→Boston should be 200-400 road miles")
     }
 
     @Test("build: three stops creates two segments")