Fix header bouncing and add private message notifications

- Fix header bar height to prevent bouncing when switching views
- Add in-app notification banner for incoming private messages
- Show orange notification that slides down from top
- Tap notification to jump directly to private chat
- Use medium haptic feedback for private messages (iOS)
- Auto-dismiss notifications after 3 seconds

bitchat/ViewModels/ChatViewModel.swift

@@ -20,11 +20,13 @@ class ChatViewModel: ObservableObject {
     @Published var privateChats: [String: [BitchatMessage]] = [:] // peerID -> messages
     @Published var selectedPrivateChatPeer: String? = nil
     @Published var unreadPrivateMessages: Set<String> = []
+    @Published var privateMessageNotification: (sender: String, message: String)? = nil
     
     let meshService = BluetoothMeshService()
     private let userDefaults = UserDefaults.standard
     private let nicknameKey = "bitchat.nickname"
     private var nicknameSaveTimer: Timer?
+    private var notificationTimer: Timer?
     
     init() {
         loadNickname()
@@ -101,6 +103,17 @@ class ChatViewModel: ObservableObject {
         return nicknames.first(where: { $0.value == nickname })?.key
     }
     
+    private func showPrivateMessageNotification(from sender: String, content: String) {
+        // Show notification
+        privateMessageNotification = (sender: sender, message: content)
+        
+        // Auto-dismiss after 3 seconds
+        notificationTimer?.invalidate()
+        notificationTimer = Timer.scheduledTimer(withTimeInterval: 3.0, repeats: false) { [weak self] _ in
+            self?.privateMessageNotification = nil
+        }
+    }
+    
     
     func formatTimestamp(_ date: Date) -> String {
         let formatter = DateFormatter()
@@ -173,6 +186,9 @@ extension ChatViewModel: BitchatDelegate {
                 if selectedPrivateChatPeer != peerID {
                     unreadPrivateMessages.insert(peerID)
                     print("[DEBUG] Added unread message indicator for peer: \(peerID)")
+                    
+                    // Show notification banner
+                    showPrivateMessageNotification(from: message.sender, content: message.content)
                 }
             } else if message.sender == nickname {
                 // Our own message - find recipient by nickname
@@ -190,9 +206,16 @@ extension ChatViewModel: BitchatDelegate {
         }
         
         #if os(iOS)
-        // Haptic feedback for new messages
+        // Different haptic feedback for private vs public messages
+        if message.isPrivate && message.sender != nickname {
+            // Medium haptic for private messages
+            let impactFeedback = UIImpactFeedbackGenerator(style: .medium)
+            impactFeedback.impactOccurred()
+        } else {
+            // Light haptic for public messages
             let impactFeedback = UIImpactFeedbackGenerator(style: .light)
             impactFeedback.impactOccurred()
+        }
         #endif
     }
     

bitchat/Views/ContentView.swift

@@ -20,6 +20,7 @@ struct ContentView: View {
     }
     
     var body: some View {
+        ZStack {
             VStack(spacing: 0) {
                 headerView
                 Divider()
@@ -29,6 +30,40 @@ struct ContentView: View {
             }
             .background(backgroundColor)
             .foregroundColor(textColor)
+            
+            // Private message notification overlay
+            if let notification = viewModel.privateMessageNotification {
+                VStack {
+                    HStack {
+                        VStack(alignment: .leading, spacing: 4) {
+                            Text("Message from \(notification.sender)")
+                                .font(.system(size: 14, weight: .medium, design: .monospaced))
+                                .foregroundColor(.white)
+                            Text(notification.message)
+                                .font(.system(size: 12, design: .monospaced))
+                                .foregroundColor(.white.opacity(0.9))
+                                .lineLimit(2)
+                        }
+                        Spacer()
+                    }
+                    .padding()
+                    .background(Color.orange)
+                    .cornerRadius(8)
+                    .shadow(radius: 4)
+                    .padding(.horizontal)
+                    .onTapGesture {
+                        if let peerID = viewModel.getPeerIDForNickname(notification.sender) {
+                            viewModel.startPrivateChat(with: peerID)
+                            viewModel.privateMessageNotification = nil
+                        }
+                    }
+                    Spacer()
+                }
+                .padding(.top, 60)
+                .transition(.move(edge: .top).combined(with: .opacity))
+                .animation(.easeInOut, value: viewModel.privateMessageNotification)
+            }
+        }
         #if os(macOS)
         .frame(minWidth: 600, minHeight: 400)
         #endif
@@ -39,7 +74,6 @@ struct ContentView: View {
             if let privatePeerID = viewModel.selectedPrivateChatPeer,
                let privatePeerNick = viewModel.meshService.getPeerNicknames()[privatePeerID] {
                 // Private chat header
-                HStack {
                 Button(action: {
                     viewModel.endPrivateChat()
                 }) {
@@ -70,7 +104,6 @@ struct ContentView: View {
                         .font(.system(size: 14, design: .monospaced))
                 }
                 .opacity(0)
-                }
             } else {
                 // Public chat header
                 Text("bitchat")
@@ -103,8 +136,8 @@ struct ContentView: View {
                 }
             }
         }
+        .frame(height: 44) // Fixed height to prevent bouncing
         .padding(.horizontal, 12)
-        .padding(.vertical, 8)
         .background(backgroundColor.opacity(0.95))
     }