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/TravelEstimatorTests.swift

@@ -232,18 +232,16 @@ struct TravelEstimatorTests {
 
     @Test("calculateTravelDays: all dates are start of day")
     func calculateTravelDays_allDatesAreStartOfDay() {
-        let calendar = TestClock.calendar
-        // Use a specific time that's not midnight
-        var components = calendar.dateComponents([.year, .month, .day], from: TestClock.now)
-        components.hour = 14
-        components.minute = 30
-        let departure = calendar.date(from: components)!
+        // Production calculateTravelDays uses Calendar.current for startOfDay,
+        // so assert with Calendar.current to match.
+        let departure = TestFixtures.date(year: 2026, month: 6, day: 15, hour: 14, minute: 30)
 
         let days = TravelEstimator.calculateTravelDays(departure: departure, drivingHours: 20)
 
+        let systemCalendar = Calendar.current
         for day in days {
-            let hour = calendar.component(.hour, from: day)
-            let minute = calendar.component(.minute, from: day)
+            let hour = systemCalendar.component(.hour, from: day)
+            let minute = systemCalendar.component(.minute, from: day)
             #expect(hour == 0 && minute == 0, "Expected midnight, got \(hour):\(minute)")
         }
     }
@@ -411,7 +409,7 @@ struct TravelEstimatorTests {
     func edge_negativeDrivingHours() {
         let departure = TestClock.now
         let days = TravelEstimator.calculateTravelDays(departure: departure, drivingHours: -5)
-        #expect(days.count >= 1, "Negative hours should still return at least 1 day")
+        #expect(days.count == 1, "Negative hours should be treated as zero driving, returning exactly 1 day")
     }
 
     // MARK: - Helper Methods