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/CommunityEvent.swift

@@ -0,0 +1,243 @@
+import Foundation
+import SwiftUI
+
+// MARK: - Community Event
+
+struct CommunityEvent: Identifiable, Equatable, Codable {
+    let id: String
+    let title: String
+    let description: String
+    let eventType: EventType
+    let location: String
+    let latitude: Double
+    let longitude: Double
+    let startDate: Date
+    let endDate: Date
+    let distanceKm: Double?
+    let organizerId: String
+    let organizerName: String
+    let maxParticipants: Int?
+    let participantCount: Int
+    let imageUrl: String?
+    let difficulty: Difficulty?
+    var rsvpStatus: RSVPStatus
+    let createdAt: Date
+
+    enum CodingKeys: String, CodingKey {
+        case id, title, description, eventType, location, latitude, longitude, startDate, endDate, distanceKm, organizerId, organizerName, maxParticipants, participantCount, imageUrl, difficulty, rsvpStatus, createdAt
+    }
+
+    init(
+        id: String,
+        title: String,
+        description: String,
+        eventType: EventType,
+        location: String,
+        latitude: Double,
+        longitude: Double,
+        startDate: Date,
+        endDate: Date,
+        distanceKm: Double?,
+        organizerId: String,
+        organizerName: String,
+        maxParticipants: Int?,
+        participantCount: Int,
+        imageUrl: String?,
+        difficulty: Difficulty?,
+        rsvpStatus: RSVPStatus,
+        createdAt: Date
+    ) {
+        self.id = id
+        self.title = title
+        self.description = description
+        self.eventType = eventType
+        self.location = location
+        self.latitude = latitude
+        self.longitude = longitude
+        self.startDate = startDate
+        self.endDate = endDate
+        self.distanceKm = distanceKm
+        self.organizerId = organizerId
+        self.organizerName = organizerName
+        self.maxParticipants = maxParticipants
+        self.participantCount = participantCount
+        self.imageUrl = imageUrl
+        self.difficulty = difficulty
+        self.rsvpStatus = rsvpStatus
+        self.createdAt = createdAt
+    }
+
+    static func == (lhs: CommunityEvent, rhs: CommunityEvent) -> Bool {
+        lhs.id == rhs.id && lhs.rsvpStatus == rhs.rsvpStatus
+    }
+
+    var isUpcoming: Bool {
+        startDate > Date()
+    }
+
+    var isOngoing: Bool {
+        Date() >= startDate && Date() <= endDate
+    }
+
+    var isPast: Bool {
+        endDate < Date()
+    }
+
+    var availableSpots: Int? {
+        guard let max = maxParticipants else { return nil }
+        return max - participantCount
+    }
+}
+
+// MARK: - Event Type
+
+enum EventType: String, CaseIterable, Codable {
+    case groupRun
+    case race
+    case workshop
+    case socialGather
+    case charityEvent
+    case trainingCamp
+
+    var displayName: String {
+        switch self {
+        case .groupRun: return "Group Run"
+        case .race: return "Race"
+        case .workshop: return "Workshop"
+        case .socialGather: return "Social"
+        case .charityEvent: return "Charity"
+        case .trainingCamp: return "Training Camp"
+        }
+    }
+
+    var icon: String {
+        switch self {
+        case .groupRun: return "person.3.fill"
+        case .race: return "flag.fill"
+        case .workshop: return "lightbulb.fill"
+        case .socialGather: return "cup.and.saucer.fill"
+        case .charityEvent: return "heart.fill"
+        case .trainingCamp: return "figure.run"
+        }
+    }
+
+    var color: Color {
+        switch self {
+        case .groupRun: return .blue
+        case .race: return .orange
+        case .workshop: return .purple
+        case .socialGather: return .green
+        case .charityEvent: return .red
+        case .trainingCamp: return .indigo
+        }
+    }
+}
+
+// MARK: - RSVP Status
+
+enum RSVPStatus: String, CaseIterable, Codable {
+    case going
+    case maybe
+    case notGoing
+    case pending
+}
+
+// MARK: - Event Participant
+
+struct EventParticipant: Identifiable, Codable {
+    let id: String
+    let name: String
+    let avatarUrl: String?
+    let rsvpStatus: RSVPStatus
+    let joinedAt: Date
+}
+
+// MARK: - Create Event Request
+
+struct CreateEventRequest: Encodable {
+    let title: String
+    let description: String
+    let eventType: EventType
+    let location: String
+    let latitude: Double
+    let longitude: Double
+    let startDate: Date
+    let endDate: Date
+    let distanceKm: Double?
+    let maxParticipants: Int?
+    let difficulty: Difficulty?
+}
+
+// MARK: - Update Event Request
+
+struct UpdateEventRequest: Encodable {
+    var title: String?
+    var description: String?
+    var eventType: EventType?
+    var location: String?
+    var latitude: Double?
+    var longitude: Double?
+    var startDate: Date?
+    var endDate: Date?
+    var distanceKm: Double?
+    var maxParticipants: Int?
+}
+
+// MARK: - Event Filter
+
+struct EventFilter: Encodable {
+    var eventType: EventType?
+    var startDate: Date?
+    var endDate: Date?
+    var location: String?
+    var radiusKm: Double?
+    var rsvpStatus: RSVPStatus?
+    var limit: Int
+    var offset: Int
+
+    init(
+        eventType: EventType? = nil,
+        startDate: Date? = nil,
+        endDate: Date? = nil,
+        location: String? = nil,
+        radiusKm: Double? = nil,
+        rsvpStatus: RSVPStatus? = nil,
+        limit: Int = 20,
+        offset: Int = 0
+    ) {
+        self.eventType = eventType
+        self.startDate = startDate
+        self.endDate = endDate
+        self.location = location
+        self.radiusKm = radiusKm
+        self.rsvpStatus = rsvpStatus
+        self.limit = limit
+        self.offset = offset
+    }
+}
+
+// MARK: - API Response Types
+
+struct EventListResponse: Decodable {
+    let events: [CommunityEvent]
+    let hasMore: Bool
+}
+
+struct EventDetailResponse: Decodable {
+    let event: CommunityEvent
+    let participants: [EventParticipant]
+}
+
+struct CreateEventResponse: Decodable {
+    let event: CommunityEvent
+}
+
+struct UpdateEventResponse: Decodable {
+    let event: CommunityEvent
+}
+
+struct RSVPResponse: Decodable {
+    let success: Bool
+    let eventId: String
+    let status: RSVPStatus
+}