feat: Sync tab, hamburger menu, network status, browse UX

- Replace History tab with Sync tab (file list, NAS status, free-up-space retention)
- Add AppMenuView hamburger sheet (History, Errors, Connection Status, Sync Activity)
- BackupView: Kisani logo chip in toolbar, hamburger menu button, swipeable ring
  pages (progress/pending/failed/uploaded), always-visible compact stats strip
- SettingsView: NETWORK section (SSID, NAS reachability, trusted-network warning,
  refresh button)
- BrowseView: pull-to-refresh, long-press context menu on items
- LANMonitor: nasReachable, nasCheckTime, checkNASReachability(host:port:)
- ConnectionStore: localRetentionDays (0/60/90/365 days)
- Regenerate xcodeproj with xcodegen to include new files

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Services/LANMonitor.swift

@@ -13,6 +13,8 @@ final class LANMonitor: ObservableObject {
     @Published private(set) var currentSSID: String? = nil
     @Published private(set) var isOnCellular: Bool = false
     @Published private(set) var isTailscaleActive: Bool = false
+    @Published private(set) var nasReachable: Bool? = nil
+    @Published private(set) var nasCheckTime: Date? = nil
 
     private let monitor = NWPathMonitor()
     private let queue = DispatchQueue(label: "com.albert.nasbackup.lan", qos: .utility)
@@ -67,7 +69,7 @@ final class LANMonitor: ObservableObject {
         UIApplication.shared.open(url)
     }
 
-    private func checkSSID() async {
+    func checkSSID() async {
         currentSSID = await fetchCurrentSSID()
     }
 
@@ -79,6 +81,42 @@ final class LANMonitor: ObservableObject {
         }
     }
 
+    func checkNASReachability(host: String, port: Int) async {
+        let ep = NWEndpoint.hostPort(
+            host: NWEndpoint.Host(host),
+            port: NWEndpoint.Port(rawValue: UInt16(port)) ?? 445
+        )
+        let connection = NWConnection(to: ep, using: .tcp)
+        var done = false
+
+        let reachable = await withCheckedContinuation { (cont: CheckedContinuation<Bool, Never>) in
+            connection.stateUpdateHandler = { state in
+                guard !done else { return }
+                switch state {
+                case .ready:
+                    done = true
+                    connection.cancel()
+                    cont.resume(returning: true)
+                case .failed, .waiting:
+                    done = true
+                    connection.cancel()
+                    cont.resume(returning: false)
+                default: break
+                }
+            }
+            connection.start(queue: queue)
+            DispatchQueue.global().asyncAfter(deadline: .now() + 4) {
+                guard !done else { return }
+                done = true
+                connection.cancel()
+                cont.resume(returning: false)
+            }
+        }
+
+        nasReachable = reachable
+        nasCheckTime = Date()
+    }
+
     func checkAndTriggerIfTrusted(trustedSSIDs: [String]) async {
         let ssid = await fetchCurrentSSID()
         guard let ssid, trustedSSIDs.contains(ssid) else { return }