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/Planning/Engine/ScenarioPlanner.swift

@@ -58,6 +58,14 @@ enum ScenarioPlannerFactory {
             return ScenarioEPlanner()
         }
 
+        // Scenario D fallback: Team-First with single team → follow that team
+        if request.preferences.planningMode == .teamFirst &&
+           request.preferences.selectedTeamIds.count == 1 {
+            // Single team in teamFirst mode → treat as follow-team
+            print("🔍 ScenarioPlannerFactory: → ScenarioDPlanner (team-first single team)")
+            return ScenarioDPlanner()
+        }
+
         // Scenario D: User wants to follow a specific team
         if request.preferences.followTeamId != nil {
             print("🔍 ScenarioPlannerFactory: → ScenarioDPlanner (follow team)")
@@ -94,6 +102,11 @@ enum ScenarioPlannerFactory {
            request.preferences.selectedTeamIds.count >= 2 {
             return .scenarioE
         }
+        // Scenario D fallback: Team-First with single team → follow that team
+        if request.preferences.planningMode == .teamFirst &&
+           request.preferences.selectedTeamIds.count == 1 {
+            return .scenarioD
+        }
         if request.preferences.followTeamId != nil {
             return .scenarioD
         }