feat: add Follow Team Mode (Scenario D) for road trip planning

Adds a new planning mode that lets users follow a team's schedule
(home + away games) and builds multi-city routes accordingly.

Key changes:
- New ScenarioDPlanner with team filtering and route generation
- Team picker UI with sport grouping and search
- Fix TravelEstimator 5-day limit (was 2-day) for cross-country routes
- Fix DateInterval end boundary to include games on last day
- Comprehensive test suite covering edge cases:
  - Multi-city routes with adequate/insufficient time
  - Optimal game selection per city for feasibility
  - 5-day driving segment limits
  - Multiple driver scenarios

Enables trips like Houston → Chicago → Anaheim following the Astros.

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

SportsTime/Core/Models/Domain/TripPreferences.swift

@@ -12,6 +12,7 @@ enum PlanningMode: String, Codable, CaseIterable, Identifiable {
     case dateRange      // Start date + end date, find games in range
     case gameFirst      // Pick games first, trip around those games
     case locations      // Start/end locations, optional games along route
+    case followTeam     // Follow one team's schedule (home + away)
 
     var id: String { rawValue }
 
@@ -20,6 +21,7 @@ enum PlanningMode: String, Codable, CaseIterable, Identifiable {
         case .dateRange: return "By Dates"
         case .gameFirst: return "By Games"
         case .locations: return "By Route"
+        case .followTeam: return "Follow Team"
         }
     }
 
@@ -28,6 +30,7 @@ enum PlanningMode: String, Codable, CaseIterable, Identifiable {
         case .dateRange: return "Shows a curated sample of possible routes — use filters to find your ideal trip"
         case .gameFirst: return "Build trip around specific games"
         case .locations: return "Plan route between locations"
+        case .followTeam: return "Follow your team on the road"
         }
     }
 
@@ -36,6 +39,7 @@ enum PlanningMode: String, Codable, CaseIterable, Identifiable {
         case .dateRange: return "calendar"
         case .gameFirst: return "sportscourt"
         case .locations: return "map"
+        case .followTeam: return "person.3.fill"
         }
     }
 }
@@ -230,6 +234,12 @@ struct TripPreferences: Codable, Hashable {
     var allowRepeatCities: Bool
     var selectedRegions: Set<Region>
 
+    /// Team to follow (for Follow Team mode)
+    var followTeamId: UUID?
+
+    /// Whether to start/end from a home location (vs fly-in/fly-out)
+    var useHomeLocation: Bool
+
     init(
         planningMode: PlanningMode = .dateRange,
         startLocation: LocationInput? = nil,
@@ -250,7 +260,9 @@ struct TripPreferences: Codable, Hashable {
         numberOfDrivers: Int = 1,
         maxDrivingHoursPerDriver: Double? = nil,
         allowRepeatCities: Bool = true,
-        selectedRegions: Set<Region> = [.east, .central, .west]
+        selectedRegions: Set<Region> = [.east, .central, .west],
+        followTeamId: UUID? = nil,
+        useHomeLocation: Bool = true
     ) {
         self.planningMode = planningMode
         self.startLocation = startLocation
@@ -272,6 +284,8 @@ struct TripPreferences: Codable, Hashable {
         self.maxDrivingHoursPerDriver = maxDrivingHoursPerDriver
         self.allowRepeatCities = allowRepeatCities
         self.selectedRegions = selectedRegions
+        self.followTeamId = followTeamId
+        self.useHomeLocation = useHomeLocation
     }
 
     var totalDriverHoursPerDay: Double {