FRE-4665: Implement Phase 3 AI training plans and premium features

- Models: TrainingPlan, Race, FamilyPlan, BeginnerMode, CommunityEvent
- Services: 5 service layers with protocol-based architecture
- ViewModels: 5 view models with @MainActor ObservableObject pattern
- Views: 10 SwiftUI views for all Phase 3 features
- Updated README with full Phase 3 documentation

Co-Authored-By: Paperclip <noreply@paperclip.ing>

Lendair/Models/Race.swift

@@ -0,0 +1,183 @@
+import Foundation
+import SwiftUI
+
+// MARK: - Race
+
+struct Race: Identifiable, Equatable, Codable {
+    let id: String
+    let name: String
+    let description: String
+    let location: String
+    let latitude: Double
+    let longitude: Double
+    let raceDate: Date
+    let distanceKm: Double
+    let raceType: RaceType
+    let organizerName: String
+    let registrationUrl: String?
+    let imageUrl: String?
+    let participantCount: Int?
+    let isRegistered: Bool
+    let isSaved: Bool
+    let elevationGain: Double
+    let terrainType: TerrainType
+
+    enum CodingKeys: String, CodingKey {
+        case id, name, description, location, latitude, longitude, raceDate, distanceKm, raceType, organizerName, registrationUrl, imageUrl, participantCount, isRegistered, isSaved, elevationGain, terrainType
+    }
+
+    init(
+        id: String,
+        name: String,
+        description: String,
+        location: String,
+        latitude: Double,
+        longitude: Double,
+        raceDate: Date,
+        distanceKm: Double,
+        raceType: RaceType,
+        organizerName: String,
+        registrationUrl: String?,
+        imageUrl: String?,
+        participantCount: Int?,
+        isRegistered: Bool,
+        isSaved: Bool,
+        elevationGain: Double,
+        terrainType: TerrainType
+    ) {
+        self.id = id
+        self.name = name
+        self.description = description
+        self.location = location
+        self.latitude = latitude
+        self.longitude = longitude
+        self.raceDate = raceDate
+        self.distanceKm = distanceKm
+        self.raceType = raceType
+        self.organizerName = organizerName
+        self.registrationUrl = registrationUrl
+        self.imageUrl = imageUrl
+        self.participantCount = participantCount
+        self.isRegistered = isRegistered
+        self.isSaved = isSaved
+        self.elevationGain = elevationGain
+        self.terrainType = terrainType
+    }
+
+    static func == (lhs: Race, rhs: Race) -> Bool {
+        lhs.id == rhs.id && lhs.isRegistered == rhs.isRegistered && lhs.isSaved == rhs.isSaved
+    }
+
+    var daysUntilRace: Int {
+        let calendar = Calendar.current
+        return calendar.dateComponents([.day], from: Date(), to: raceDate).day ?? 0
+    }
+
+    var isUpcoming: Bool {
+        raceDate > Date()
+    }
+}
+
+// MARK: - Race Type
+
+enum RaceType: String, CaseIterable, Codable {
+    case road
+    case trail
+    case track
+    case virtual
+
+    var displayName: String {
+        switch self {
+        case .road: return "Road"
+        case .trail: return "Trail"
+        case .track: return "Track"
+        case .virtual: return "Virtual"
+        }
+    }
+
+    var icon: String {
+        switch self {
+        case .road: return "car.fill"
+        case .trail: return "mountain.2.fill"
+        case .track: return "circle.fill"
+        case .virtual: return "globe"
+        }
+    }
+}
+
+// MARK: - Terrain Type
+
+enum TerrainType: String, CaseIterable, Codable {
+    case flat
+    case rolling
+    case hilly
+    case mountainous
+
+    var displayName: String {
+        switch self {
+        case .flat: return "Flat"
+        case .rolling: return "Rolling"
+        case .hilly: return "Hilly"
+        case .mountainous: return "Mountainous"
+        }
+    }
+}
+
+// MARK: - Race Filter
+
+struct RaceFilter: Encodable {
+    var distanceKm: Double?
+    var raceType: RaceType?
+    var terrainType: TerrainType?
+    var startDate: Date?
+    var endDate: Date?
+    var location: String?
+    var radiusKm: Double?
+    var limit: Int
+    var offset: Int
+
+    init(
+        distanceKm: Double? = nil,
+        raceType: RaceType? = nil,
+        terrainType: TerrainType? = nil,
+        startDate: Date? = nil,
+        endDate: Date? = nil,
+        location: String? = nil,
+        radiusKm: Double? = nil,
+        limit: Int = 20,
+        offset: Int = 0
+    ) {
+        self.distanceKm = distanceKm
+        self.raceType = raceType
+        self.terrainType = terrainType
+        self.startDate = startDate
+        self.endDate = endDate
+        self.location = location
+        self.radiusKm = radiusKm
+        self.limit = limit
+        self.offset = offset
+    }
+}
+
+// MARK: - API Response Types
+
+struct RaceListResponse: Decodable {
+    let races: [Race]
+    let hasMore: Bool
+}
+
+struct RaceDetailResponse: Decodable {
+    let race: Race
+}
+
+struct SaveRaceResponse: Decodable {
+    let success: Bool
+    let raceId: String
+    let isSaved: Bool
+}
+
+struct RegisterRaceResponse: Decodable {
+    let success: Bool
+    let raceId: String
+    let registrationUrl: String?
+}