Add persistent app quit control

FchatiApp/Sources/FchatiApp/FchatiApp.swift

@@ -1,3 +1,4 @@
+import AppKit
 import SwiftUI
 
 @main
@@ -38,6 +39,7 @@ private struct RootView: View {
 
     var body: some View {
         VStack(spacing: 0) {
+            HStack(spacing: 8) {
                 Picker("Section", selection: $selectedTab) {
                     ForEach(AppTab.allCases) { tab in
                         Label(tab.title, systemImage: tab.icon)
@@ -46,6 +48,15 @@ private struct RootView: View {
                 }
                 .pickerStyle(.segmented)
                 .labelsHidden()
+
+                Button {
+                    NSApplication.shared.terminate(nil)
+                } label: {
+                    Image(systemName: "power")
+                }
+                .accessibilityLabel("Quit Fchati")
+                .help("Quit Fchati")
+            }
             .padding()
 
             Divider()

IMPLEMENTATION_STATUS.md

@@ -197,6 +197,7 @@
 - The relay now defaults to the production Traefik certificate resolver (`myresolver`) and allows a host-specific override through `TRAEFIK_CERT_RESOLVER`.
 - Corrected the production hostname to `fchaty.diyaa.de` in the relay route and macOS application HTTP and WebSocket clients.
 - `relay-server/Dockerfile` initializes all persistent-data paths as the unprivileged `node` user, preventing pairing, queue, and upload write failures on newly created volumes.
+- The macOS app now has an always-visible quit control beside the top-level tabs, in addition to the existing Settings action.
 
 ## Bug Fixes — Post-Review ✅