refactor: Remove NWPathMonitor auto-sync, keep only on-demand server checks

- Delete NetworkConnectivity.swift with problematic NWPathMonitor
- Remove serverDidBecomeAvailable notification
- Remove unused startAutoSync from OfflineSyncManager
- Server check now only on app start via AppViewModel

readeck/Data/Repository/OfflineSyncManager.swift

@@ -124,22 +124,4 @@ class OfflineSyncManager: ObservableObject, @unchecked Sendable {
         }
     }
     
-    // MARK: - Auto Sync on Server Connectivity Changes
-    
-    func startAutoSync() {
-        // Monitor server connectivity and auto-sync when server becomes reachable
-        NotificationCenter.default.addObserver(
-            forName: .serverDidBecomeAvailable,
-            object: nil,
-            queue: .main
-        ) { [weak self] _ in
-            Task {
-                await self?.syncOfflineBookmarks()
-            }
-        }
-    }
-    
-    deinit {
-        NotificationCenter.default.removeObserver(self)
-    }
 }

readeck/Data/Utils/NetworkConnectivity.swift

@@ -1,50 +0,0 @@
-import Foundation
-import Network
-
-class ServerConnectivity: ObservableObject {
-    private let monitor = NWPathMonitor()
-    private let queue = DispatchQueue.global(qos: .background)
-    
-    @Published var isServerReachable = false
-    
-    static let shared = ServerConnectivity()
-    
-    private init() {
-        startMonitoring()
-    }
-    
-    private func startMonitoring() {
-        monitor.pathUpdateHandler = { [weak self] path in
-            if path.status == .satisfied {
-                // Network is available, now check server
-                Task {
-                    let serverReachable = await ServerConnectivity.isServerReachable()
-                    DispatchQueue.main.async {
-                        let wasReachable = self?.isServerReachable ?? false
-                        self?.isServerReachable = serverReachable
-                        
-                        // Notify when server becomes available
-                        if !wasReachable && serverReachable {
-                            NotificationCenter.default.post(name: .serverDidBecomeAvailable, object: nil)
-                        }
-                    }
-                }
-            } else {
-                DispatchQueue.main.async {
-                    self?.isServerReachable = false
-                }
-            }
-        }
-        monitor.start(queue: queue)
-    }
-    
-    deinit {
-        monitor.cancel()
-    }
-    
-    // Check if the Readeck server endpoint is reachable
-    static func isServerReachable() async -> Bool {
-        let useCase = DefaultUseCaseFactory.shared.makeCheckServerReachabilityUseCase()
-        return await useCase.execute()
-    }
-}

readeck/UI/Utils/NotificationNames.swift

@@ -8,9 +8,6 @@ extension Notification.Name {
     // MARK: - Authentication
     static let unauthorizedAPIResponse = Notification.Name("UnauthorizedAPIResponse")
 
-    // MARK: - Network
-    static let serverDidBecomeAvailable = Notification.Name("ServerDidBecomeAvailable")
-    
     // MARK: - UI Interactions
     static let dismissKeyboard = Notification.Name("DismissKeyboard")
     static let addBookmarkFromShare = Notification.Name("AddBookmarkFromShare")