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/Features/Trip/Views/TripCreationView.swift

@@ -73,6 +73,12 @@ struct TripCreationView: View {
                         sportsSection
                         datesSection
                         gamesSection
+
+                    case .followTeam:
+                        // Team picker + Dates + Home location toggle
+                        teamPickerSection
+                        datesSection
+                        homeLocationSection
                     }
 
                     // Common sections
@@ -516,6 +522,113 @@ struct TripCreationView: View {
         }
     }
 
+    // MARK: - Follow Team Mode
+
+    @State private var showTeamPicker = false
+
+    private var teamPickerSection: some View {
+        ThemedSection(title: "Select Team") {
+            Button {
+                showTeamPicker = true
+            } label: {
+                HStack(spacing: Theme.Spacing.md) {
+                    ZStack {
+                        Circle()
+                            .fill(Theme.warmOrange.opacity(0.15))
+                            .frame(width: 40, height: 40)
+                        Image(systemName: "person.3.fill")
+                            .foregroundStyle(Theme.warmOrange)
+                    }
+
+                    VStack(alignment: .leading, spacing: 2) {
+                        if let team = viewModel.followedTeam {
+                            Text(team.name)
+                                .font(.body)
+                                .foregroundStyle(Theme.textPrimary(colorScheme))
+                            Text(team.sport.displayName)
+                                .font(.caption)
+                                .foregroundStyle(Theme.textSecondary(colorScheme))
+                        } else {
+                            Text("Choose a team")
+                                .font(.body)
+                                .foregroundStyle(Theme.textPrimary(colorScheme))
+                            Text("Pick the team to follow")
+                                .font(.caption)
+                                .foregroundStyle(Theme.textMuted(colorScheme))
+                        }
+                    }
+
+                    Spacer()
+
+                    Image(systemName: "chevron.right")
+                        .foregroundStyle(Theme.textMuted(colorScheme))
+                }
+                .padding(Theme.Spacing.md)
+                .background(Theme.cardBackgroundElevated(colorScheme))
+                .clipShape(RoundedRectangle(cornerRadius: Theme.CornerRadius.medium))
+            }
+            .buttonStyle(.plain)
+        }
+        .sheet(isPresented: $showTeamPicker) {
+            TeamPickerSheet(
+                selectedTeamId: $viewModel.followTeamId,
+                teamsBySport: viewModel.teamsBySport
+            )
+        }
+    }
+
+    private var homeLocationSection: some View {
+        ThemedSection(title: "Trip Start/End") {
+            VStack(spacing: Theme.Spacing.md) {
+                ThemedToggle(
+                    label: "Start and end from home",
+                    isOn: $viewModel.useHomeLocation,
+                    icon: "house.fill"
+                )
+
+                if viewModel.useHomeLocation {
+                    // Show home location input with suggestions
+                    VStack(alignment: .leading, spacing: 0) {
+                        ThemedTextField(
+                            label: "Home Location",
+                            placeholder: "Enter your city",
+                            text: $viewModel.startLocationText,
+                            icon: "house.fill"
+                        )
+                        .onChange(of: viewModel.startLocationText) { _, newValue in
+                            searchLocation(query: newValue, isStart: true)
+                        }
+
+                        // Suggestions for home location
+                        if !startLocationSuggestions.isEmpty {
+                            locationSuggestionsList(
+                                suggestions: startLocationSuggestions,
+                                isLoading: isSearchingStart
+                            ) { result in
+                                viewModel.startLocationText = result.name
+                                viewModel.startLocation = result.toLocationInput()
+                                startLocationSuggestions = []
+                            }
+                        } else if isSearchingStart {
+                            HStack {
+                                ThemedSpinnerCompact(size: 14)
+                                Text("Searching...")
+                                    .font(.subheadline)
+                                    .foregroundStyle(Theme.textMuted(colorScheme))
+                            }
+                            .padding(.top, Theme.Spacing.xs)
+                        }
+                    }
+                } else {
+                    Text("Trip will start at first game and end at last game (fly-in/fly-out)")
+                        .font(.caption)
+                        .foregroundStyle(Theme.textMuted(colorScheme))
+                        .padding(.leading, 32)
+                }
+            }
+        }
+    }
+
     private var gamesSection: some View {
         ThemedSection(title: "Must-See Games") {
             Button {
@@ -2205,6 +2318,114 @@ struct DayCell: View {
     }
 }
 
+// MARK: - Team Picker Sheet
+
+struct TeamPickerSheet: View {
+    @Binding var selectedTeamId: UUID?
+    let teamsBySport: [Sport: [Team]]
+
+    @Environment(\.dismiss) private var dismiss
+    @Environment(\.colorScheme) private var colorScheme
+
+    @State private var searchText = ""
+
+    private var sortedSports: [Sport] {
+        Sport.allCases.filter { teamsBySport[$0] != nil && !teamsBySport[$0]!.isEmpty }
+    }
+
+    private var filteredTeamsBySport: [Sport: [Team]] {
+        guard !searchText.isEmpty else { return teamsBySport }
+
+        var filtered: [Sport: [Team]] = [:]
+        for (sport, teams) in teamsBySport {
+            let matchingTeams = teams.filter {
+                $0.name.localizedCaseInsensitiveContains(searchText) ||
+                $0.city.localizedCaseInsensitiveContains(searchText) ||
+                $0.abbreviation.localizedCaseInsensitiveContains(searchText)
+            }
+            if !matchingTeams.isEmpty {
+                filtered[sport] = matchingTeams
+            }
+        }
+        return filtered
+    }
+
+    var body: some View {
+        NavigationStack {
+            List {
+                ForEach(sortedSports, id: \.self) { sport in
+                    if let teams = filteredTeamsBySport[sport], !teams.isEmpty {
+                        Section(sport.displayName) {
+                            ForEach(teams) { team in
+                                TeamRow(
+                                    team: team,
+                                    isSelected: selectedTeamId == team.id,
+                                    colorScheme: colorScheme
+                                ) {
+                                    selectedTeamId = team.id
+                                    dismiss()
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+            .searchable(text: $searchText, prompt: "Search teams")
+            .navigationTitle("Select Team")
+            .navigationBarTitleDisplayMode(.inline)
+            .toolbar {
+                ToolbarItem(placement: .cancellationAction) {
+                    Button("Cancel") {
+                        dismiss()
+                    }
+                }
+            }
+        }
+    }
+}
+
+struct TeamRow: View {
+    let team: Team
+    let isSelected: Bool
+    let colorScheme: ColorScheme
+    let onTap: () -> Void
+
+    var body: some View {
+        Button(action: onTap) {
+            HStack(spacing: Theme.Spacing.md) {
+                // Team color indicator
+                if let colorHex = team.primaryColor {
+                    Circle()
+                        .fill(Color(hex: colorHex))
+                        .frame(width: 12, height: 12)
+                } else {
+                    Circle()
+                        .fill(Theme.warmOrange)
+                        .frame(width: 12, height: 12)
+                }
+
+                VStack(alignment: .leading, spacing: 2) {
+                    Text(team.name)
+                        .font(.body)
+                        .foregroundStyle(Theme.textPrimary(colorScheme))
+                    Text(team.city)
+                        .font(.caption)
+                        .foregroundStyle(Theme.textSecondary(colorScheme))
+                }
+
+                Spacer()
+
+                if isSelected {
+                    Image(systemName: "checkmark.circle.fill")
+                        .foregroundStyle(Theme.warmOrange)
+                }
+            }
+            .contentShape(Rectangle())
+        }
+        .buttonStyle(.plain)
+    }
+}
+
 #Preview {
     TripCreationView(viewModel: TripCreationViewModel())
 }