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>

SportsTimeTests/Planning/TripPlanningEngineTests.swift

@@ -122,7 +122,7 @@ struct TripPlanningEngineTests {
             endDate: endDate,
             tripDuration: nil
         )
-        #expect(prefs.effectiveTripDuration == 7)
+        #expect(prefs.effectiveTripDuration == 8) // 8 days inclusive (15th through 22nd)
     }
 
     // MARK: - Invariant Tests