feat(wizard): add mode-specific trip wizard inputs

- Add GamePickerStep with sheet-based Sport → Team → Game selection
- Add TeamPickerStep with sheet-based Sport → Team selection
- Add LocationsStep for start/end location selection with round trip toggle
- Update TripWizardViewModel with mode-specific fields and validation
- Update TripWizardView with conditional step rendering per mode
- Update ReviewStep with mode-aware validation display
- Fix gameFirst mode to derive date range from selected games

Each planning mode now shows only relevant steps:
- By Dates: Dates → Sports → Regions → Route → Repeat → Must Stops
- By Games: Game Picker → Route → Repeat → Must Stops
- By Route: Locations → Dates → Sports → Route → Repeat → Must Stops
- Follow Team: Team Picker → Dates → Route → Repeat → Must Stops

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

SportsTime/Features/Trip/ViewModels/TripWizardViewModel.swift

@@ -49,6 +49,22 @@ final class TripWizardViewModel {
 
     var mustStopLocations: [LocationInput] = []
 
+    // MARK: - Mode-Specific: gameFirst (cascading selection)
+
+    var gamePickerSports: Set<Sport> = []
+    var gamePickerTeamIds: Set<String> = []
+    var selectedGameIds: Set<String> = []
+
+    // MARK: - Mode-Specific: followTeam
+
+    var selectedTeamId: String? = nil
+    var teamPickerSport: Sport? = nil
+
+    // MARK: - Mode-Specific: locations
+
+    var startLocation: LocationInput? = nil
+    var endLocation: LocationInput? = nil
+
     // MARK: - Planning State
 
     var isPlanning: Bool = false
@@ -65,26 +81,65 @@ final class TripWizardViewModel {
         planningMode != nil
     }
 
+    /// Mode-specific step visibility
+    var showDatesStep: Bool {
+        planningMode == .dateRange || planningMode == .followTeam || planningMode == .locations
+    }
+
+    var showSportsStep: Bool {
+        planningMode == .dateRange || planningMode == .locations
+    }
+
+    var showRegionsStep: Bool {
+        planningMode == .dateRange
+    }
+
+    var showGamePickerStep: Bool {
+        planningMode == .gameFirst
+    }
+
+    var showTeamPickerStep: Bool {
+        planningMode == .followTeam
+    }
+
+    var showLocationsStep: Bool {
+        planningMode == .locations
+    }
+
     // MARK: - Validation
 
     /// All required fields must be set before planning
     var canPlanTrip: Bool {
-        planningMode != nil &&
-        hasSetDates &&
-        !selectedSports.isEmpty &&
-        !selectedRegions.isEmpty &&
-        hasSetRoutePreference &&
-        hasSetRepeatCities
+        guard let mode = planningMode else { return false }
+
+        // Common requirements for all modes
+        guard hasSetRoutePreference && hasSetRepeatCities else { return false }
+
+        switch mode {
+        case .dateRange:
+            return hasSetDates && !selectedSports.isEmpty && !selectedRegions.isEmpty
+        case .gameFirst:
+            return !selectedGameIds.isEmpty
+        case .locations:
+            return startLocation != nil && endLocation != nil && hasSetDates && !selectedSports.isEmpty
+        case .followTeam:
+            return selectedTeamId != nil && hasSetDates
+        }
     }
 
     /// Field validation for the review step - shows which fields are missing
     var fieldValidation: FieldValidation {
         FieldValidation(
+            planningMode: planningMode,
             sports: selectedSports.isEmpty ? .missing : .valid,
             dates: hasSetDates ? .valid : .missing,
             regions: selectedRegions.isEmpty ? .missing : .valid,
             routePreference: hasSetRoutePreference ? .valid : .missing,
-            repeatCities: hasSetRepeatCities ? .valid : .missing
+            repeatCities: hasSetRepeatCities ? .valid : .missing,
+            selectedGames: selectedGameIds.isEmpty ? .missing : .valid,
+            selectedTeam: selectedTeamId == nil ? .missing : .valid,
+            startLocation: startLocation == nil ? .missing : .valid,
+            endLocation: endLocation == nil ? .missing : .valid
         )
     }
 
@@ -123,12 +178,26 @@ final class TripWizardViewModel {
     // MARK: - Reset Logic
 
     private func resetAllSelections() {
+        // Common fields
         selectedSports = []
         hasSetDates = false
         selectedRegions = []
         hasSetRoutePreference = false
         hasSetRepeatCities = false
         mustStopLocations = []
+
+        // gameFirst mode fields
+        gamePickerSports = []
+        gamePickerTeamIds = []
+        selectedGameIds = []
+
+        // followTeam mode fields
+        selectedTeamId = nil
+        teamPickerSport = nil
+
+        // locations mode fields
+        startLocation = nil
+        endLocation = nil
     }
 }
 
@@ -140,9 +209,70 @@ struct FieldValidation {
         case missing
     }
 
+    let planningMode: PlanningMode?
+
+    // Common fields
     let sports: Status
     let dates: Status
     let regions: Status
     let routePreference: Status
     let repeatCities: Status
+
+    // Mode-specific fields
+    let selectedGames: Status
+    let selectedTeam: Status
+    let startLocation: Status
+    let endLocation: Status
+
+    /// Returns only the fields that are required for the current planning mode
+    var requiredFields: [(name: String, status: Status)] {
+        var fields: [(String, Status)] = []
+
+        guard let mode = planningMode else { return fields }
+
+        switch mode {
+        case .dateRange:
+            fields = [
+                ("Dates", dates),
+                ("Sports", sports),
+                ("Regions", regions),
+                ("Route Preference", routePreference),
+                ("Repeat Cities", repeatCities)
+            ]
+        case .gameFirst:
+            fields = [
+                ("Games", selectedGames),
+                ("Route Preference", routePreference),
+                ("Repeat Cities", repeatCities)
+            ]
+        case .locations:
+            fields = [
+                ("Start Location", startLocation),
+                ("End Location", endLocation),
+                ("Dates", dates),
+                ("Sports", sports),
+                ("Route Preference", routePreference),
+                ("Repeat Cities", repeatCities)
+            ]
+        case .followTeam:
+            fields = [
+                ("Team", selectedTeam),
+                ("Dates", dates),
+                ("Route Preference", routePreference),
+                ("Repeat Cities", repeatCities)
+            ]
+        }
+
+        return fields
+    }
+
+    /// Returns only the missing required fields for the current mode
+    var missingFields: [String] {
+        requiredFields.filter { $0.status == .missing }.map { $0.name }
+    }
+
+    /// Whether all required fields for the current mode are valid
+    var allRequiredFieldsValid: Bool {
+        requiredFields.allSatisfy { $0.status == .valid }
+    }
 }