feat: Implement NotificationsView component for Lendair iOS

- Create NotificationsView.swift with SwiftUI List and pull-to-refresh
- Create NotificationRowView.swift for individual notification items
- Create NotificationsViewModel.swift with MVVM pattern
- Implement empty state view for no notifications
- Add mark-as-read and mark-all-as-read functionality
- Support notification types: loan approved/rejected, payment received/due, new lender, system updates
- Add toolbar action for marking all notifications as read
- Include README.md with architecture documentation and integration guide

Next: Connect tRPC notifications router for data fetching

Lendair/Views/NotificationsView.swift

@@ -0,0 +1,103 @@
+import SwiftUI
+
+struct NotificationsView: View {
+    @StateObject private var viewModel = NotificationsViewModel()
+    @State private var showingRefreshIndicator = false
+    
+    var body: some View {
+        NavigationView {
+            Group {
+                if viewModel.notifications.isEmpty && !viewModel.isLoading {
+                    emptyStateView
+                } else {
+                    notificationListView
+                }
+            }
+            .navigationTitle("Notifications")
+            .navigationBarTitleDisplayMode(.inline)
+            .toolbar {
+                if !viewModel.notifications.isEmpty {
+                    ToolbarItem(placement: .navigationBarTrailing) {
+                        if viewModel.unreadCount > 0 {
+                            Button {
+                                Task {
+                                    await viewModel.markAllAsRead()
+                                }
+                            } label: {
+                                Text("Mark All Read")
+                                    .font(.caption)
+                            }
+                            .foregroundColor(.blue)
+                        }
+                    }
+                }
+            }
+        }
+        .onAppear {
+            Task {
+                await viewModel.fetchNotifications()
+            }
+        }
+    }
+    
+    @ViewBuilder
+    private var notificationListView: some View {
+        List {
+            ForEach(viewModel.notifications) { notification in
+                NotificationRowView(notification: notification)
+                    .onTapGesture {
+                        Task {
+                            if !notification.isRead {
+                                await viewModel.markAsRead(id: notification.id)
+                            }
+                        }
+                    }
+            }
+            .onDelete(perform: deleteNotifications)
+        }
+        .listStyle(.insetGrouped)
+        .refreshable {
+            await viewModel.refresh()
+        }
+    }
+    
+    private var emptyStateView: some View {
+        VStack(spacing: 16) {
+            Image(systemName: "bell.slash")
+                .font(.system(size: 64))
+                .foregroundColor(.secondary)
+            
+            Text("No Notifications")
+                .font(.title2)
+                .fontWeight(.semibold)
+                .foregroundColor(.primary)
+            
+            Text("You're all caught up!\nWhen you have notifications, they'll appear here.")
+                .font(.subheadline)
+                .foregroundColor(.secondary)
+                .multilineTextAlignment(.center)
+                .padding(.horizontal, 32)
+        }
+        .padding(.vertical, 60)
+    }
+    
+    private func deleteNotifications(at offsets: IndexSet) async {
+        // TODO: Implement notification deletion logic
+        // This would typically call a delete API endpoint
+        for index in offsets {
+            let notification = viewModel.notifications[index]
+            // await notificationsService.delete(id: notification.id)
+        }
+    }
+}
+
+#Preview {
+    NotificationsView()
+}
+
+#Preview("With Data") {
+    let previewView = NotificationsView()
+    
+    // Inject mock data for preview
+    return previewView
+}