feat: add sliding window trip generation for By Games mode

Adds a trip duration stepper (2-21 days) to the By Games planning mode.
When users select specific games, the planner now generates ALL possible
N-day windows containing those games (e.g., 7-day trips starting on
different days), finding additional games in each window to maximize
route options.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

SportsTime/Core/Models/Domain/TripPreferences.swift

@@ -240,6 +240,9 @@ struct TripPreferences: Codable, Hashable {
     /// Whether to start/end from a home location (vs fly-in/fly-out)
     var useHomeLocation: Bool
 
+    /// Trip duration for gameFirst mode sliding windows (number of days)
+    var gameFirstTripDuration: Int
+
     init(
         planningMode: PlanningMode = .dateRange,
         startLocation: LocationInput? = nil,
@@ -262,7 +265,8 @@ struct TripPreferences: Codable, Hashable {
         allowRepeatCities: Bool = true,
         selectedRegions: Set<Region> = [.east, .central, .west],
         followTeamId: UUID? = nil,
-        useHomeLocation: Bool = true
+        useHomeLocation: Bool = true,
+        gameFirstTripDuration: Int = 7
     ) {
         self.planningMode = planningMode
         self.startLocation = startLocation
@@ -286,6 +290,7 @@ struct TripPreferences: Codable, Hashable {
         self.selectedRegions = selectedRegions
         self.followTeamId = followTeamId
         self.useHomeLocation = useHomeLocation
+        self.gameFirstTripDuration = gameFirstTripDuration
     }
 
     var totalDriverHoursPerDay: Double {

SportsTime/Features/Trip/ViewModels/TripCreationViewModel.swift

@@ -137,6 +137,9 @@ final class TripCreationViewModel {
     var followTeamId: UUID?
     var useHomeLocation: Bool = true
 
+    // Game First Mode - Trip duration for sliding windows
+    var gameFirstTripDuration: Int = 7
+
     // MARK: - Dependencies
 
     private let planningEngine = TripPlanningEngine()
@@ -407,7 +410,8 @@ final class TripCreationViewModel {
             allowRepeatCities: allowRepeatCities,
             selectedRegions: selectedRegions,
             followTeamId: followTeamId,
-            useHomeLocation: useHomeLocation
+            useHomeLocation: useHomeLocation,
+            gameFirstTripDuration: gameFirstTripDuration
         )
 
         // Build planning request
@@ -589,7 +593,10 @@ final class TripCreationViewModel {
             numberOfDrivers: numberOfDrivers,
             maxDrivingHoursPerDriver: maxDrivingHoursPerDriver,
             allowRepeatCities: allowRepeatCities,
-            selectedRegions: selectedRegions
+            selectedRegions: selectedRegions,
+            followTeamId: followTeamId,
+            useHomeLocation: useHomeLocation,
+            gameFirstTripDuration: gameFirstTripDuration
         )
         return convertToTrip(option: option, preferences: preferences)
     }

SportsTime/Features/Trip/Views/TripCreationView.swift

@@ -66,9 +66,10 @@ struct TripCreationView: View {
                         datesSection
 
                     case .gameFirst:
-                        // Sports + Game Picker
+                        // Sports + Game Picker + Trip Duration
                         sportsSection
                         gameBrowserSection
+                        tripDurationSection
 
                     case .locations:
                         // Locations + Sports + optional games
@@ -512,6 +513,39 @@ struct TripCreationView: View {
         }
     }
 
+    private var tripDurationSection: some View {
+        ThemedSection(title: "Trip Duration") {
+            VStack(alignment: .leading, spacing: Theme.Spacing.sm) {
+                HStack {
+                    Image(systemName: "calendar.badge.clock")
+                        .foregroundStyle(Theme.warmOrange)
+                    Text("Days")
+                        .font(.body)
+                        .foregroundStyle(Theme.textPrimary(colorScheme))
+
+                    Spacer()
+
+                    Stepper(
+                        value: $viewModel.gameFirstTripDuration,
+                        in: 2...21,
+                        step: 1
+                    ) {
+                        Text("\(viewModel.gameFirstTripDuration) days")
+                            .font(.body.monospacedDigit())
+                            .foregroundStyle(Theme.textPrimary(colorScheme))
+                    }
+                }
+                .padding(Theme.Spacing.md)
+                .background(Theme.cardBackgroundElevated(colorScheme))
+                .clipShape(RoundedRectangle(cornerRadius: Theme.CornerRadius.medium))
+
+                Text("We'll find all possible \(viewModel.gameFirstTripDuration)-day trips that include your selected games")
+                    .font(.caption)
+                    .foregroundStyle(Theme.textSecondary(colorScheme))
+            }
+        }
+    }
+
     private var sportsSection: some View {
         ThemedSection(title: "Sports") {
             SportSelectorGrid(
@@ -1406,6 +1440,7 @@ struct LocationSearchSheet: View {
 
 enum TripSortOption: String, CaseIterable, Identifiable {
     case recommended = "Recommended"
+    case mostCities = "Most Cities"
     case mostGames = "Most Games"
     case leastGames = "Least Games"
     case mostMiles = "Most Miles"
@@ -1417,6 +1452,7 @@ enum TripSortOption: String, CaseIterable, Identifiable {
     var icon: String {
         switch self {
         case .recommended: return "star.fill"
+        case .mostCities: return "mappin.and.ellipse"
         case .mostGames, .leastGames: return "sportscourt"
         case .mostMiles, .leastMiles: return "road.lanes"
         case .bestEfficiency: return "gauge.with.dots.needle.33percent"
@@ -1514,6 +1550,8 @@ struct TripOptionsView: View {
         switch sortOption {
         case .recommended:
             return filtered
+        case .mostCities:
+            return filtered.sorted { $0.stops.count > $1.stops.count }
         case .mostGames:
             return filtered.sorted { $0.totalGames > $1.totalGames }
         case .leastGames:

SportsTime/Planning/Engine/ScenarioBPlanner.swift

@@ -221,13 +221,19 @@ final class ScenarioBPlanner: ScenarioPlanner {
         request: PlanningRequest
     ) -> [DateInterval] {
 
-        // If explicit date range exists, use it
+        // For gameFirst mode, ALWAYS use sliding windows with gameFirstTripDuration
-        if let dateRange = request.dateRange {
+        // This generates all possible N-day windows containing the selected games
+        let isGameFirstMode = request.preferences.planningMode == .gameFirst
+        let duration = isGameFirstMode
+            ? request.preferences.gameFirstTripDuration
+            : request.preferences.effectiveTripDuration
+
+        // If not gameFirst and explicit date range exists, use it directly
+        if !isGameFirstMode, let dateRange = request.dateRange {
             return [dateRange]
         }
 
-        // Otherwise, use trip duration to create sliding windows
+        // Use trip duration to create sliding windows
-        let duration = request.preferences.effectiveTripDuration
         guard duration > 0 else { return [] }
 
         // Find the span of selected games