feat(ios): tab tabanlı navigasyon ve okuma durumu takibi ekle

ios/Bookibra/Models/ReadingStatus.swift

@@ -0,0 +1,34 @@
+import Foundation
+import SwiftUI
+
+enum ReadingStatus: String, CaseIterable, Codable, Identifiable {
+    case wantToRead
+    case reading
+    case finished
+
+    var id: String { rawValue }
+
+    var title: String {
+        switch self {
+        case .wantToRead: return "Want to Read"
+        case .reading: return "Reading"
+        case .finished: return "Finished"
+        }
+    }
+
+    var symbol: String {
+        switch self {
+        case .wantToRead: return "bookmark"
+        case .reading: return "book"
+        case .finished: return "checkmark.circle"
+        }
+    }
+
+    var color: Color {
+        switch self {
+        case .wantToRead: return .orange
+        case .reading: return .blue
+        case .finished: return .green
+        }
+    }
+}