fix: 12 planning engine bugs + App Store preview export at 886x1920

Planning engine fixes (from adversarial code review):
- Bug #1: sortByLeisure tie-breaking uses totalDrivingHours
- Bug #2: allDates/calculateRestDays guard-let-break prevents infinite loop
- Bug #3: same-day trip no longer rejected (>= in dateRange guard)
- Bug #4: ScenarioD rationale shows game count not stop count
- Bug #5: ScenarioD departureDate advanced to next day after last game
- Bug #6: ScenarioC date range boundary uses <= instead of <
- Bug #7: DrivingConstraints clamps maxHoursPerDriverPerDay via max(1.0,...)
- Bug #8: effectiveTripDuration uses inclusive day counting (+1)
- Bug #9: TripWizardViewModel validates endDate >= startDate
- Bug #10: allDates() uses min/max instead of first/last for robustness
- Bug #12: arrivalBeforeGameStart accounts for game end time at departure
- Bug #15: ScenarioBPlanner replaces force unwraps with safe unwrapping

Tests: 16 regression test suites + updated existing test expectations
Marketing: Remotion canvas set to 886x1920 for App Store preview spec

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

SportsTime/Features/Trip/ViewModels/TripWizardViewModel.swift

@@ -124,6 +124,9 @@ final class TripWizardViewModel {
         // Common requirements for all modes
         guard hasSetRoutePreference && hasSetRepeatCities else { return false }
 
+        // Date validation: endDate must not be before startDate for modes that use dates
+        if hasSetDates && endDate < startDate { return false }
+
         switch mode {
         case .dateRange:
             return hasSetDates && !selectedSports.isEmpty && !selectedRegions.isEmpty