feat: Kisani rebrand, step-based onboarding flow, dark mode fixes

- Rename app to Kisani in all UI text and Face ID prompt
- Replace flat 2-state RootView with 5-step flow: ConnectView →
  LoginView → FolderSetupView → PhotoPermissionView → MainTabView
- Remove NavigationStack from LoginView (was causing nested-stack crash);
  drive navigation via ConnectionStore.isSessionActive
- Add FolderSetupView and PhotoPermissionView onboarding screens with
  step indicator (2/3, 3/3), spring entrance animations, and UGreen
  connection chip
- Fix dark mode button invisibility: PrimaryButtonStyle and PillButtonStyle
  now use AppTheme.inkInverse; GhostButtonStyle border uses ink.opacity(0.25)
- Add AppTheme.inkInverse adaptive token (dark bg ink on dark, white on light)
- Add ConnectionStore.isSessionActive (non-persisted) and
  onboardingPhotoShown (UserDefaults-persisted)
- Add os_log logging in LoginViewModel at auth start/success/failure
- Remove dead Help button from ConnectView
- UGreenCompatibilityBadge, KeychainStore, SavedConnections, extensions,
  PrivacyInfo.xcprivacy, unit test target and test stubs
- AppTheme: full UIColor dynamic provider tokens for dark/light adaptive color
- AppearanceMode enum + segmented picker in SettingsView
- BackupView: enlarged ring, removed options card and linear progress bar
- HistoryView: duration and bytes formatting, improved typography hierarchy

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

Features/Settings/LANTriggerSection.swift

@@ -131,7 +131,7 @@ struct LANTriggerSection: View {
                 .padding(.horizontal, AppTheme.cardPad)
                 .padding(.vertical, 12)
             }
-            .background(Color.white)
+            .background(AppTheme.surfaceRaised)
             .clipShape(RoundedRectangle(cornerRadius: AppTheme.radius, style: .continuous))
             .shadow(color: AppTheme.cardShadow, radius: 12, x: 0, y: 2)
         }

Features/Settings/SettingsView.swift

@@ -6,10 +6,11 @@ struct SettingsView: View {
 
     var body: some View {
         ZStack {
-            Color.white.ignoresSafeArea()
+            AppTheme.background.ignoresSafeArea()
 
             ScrollView {
                 VStack(spacing: AppTheme.sectionGap) {
+                    appearanceSection
                     LANTriggerSection()
                     mediaSection
                     quietHoursSection
@@ -26,6 +27,45 @@ struct SettingsView: View {
         .navigationBarTitleDisplayMode(.inline)
     }
 
+    // MARK: — Appearance
+
+    private var appearanceSection: some View {
+        VStack(alignment: .leading, spacing: 8) {
+            sectionLabel("APPEARANCE")
+
+            HStack(spacing: 0) {
+                ForEach(AppearanceMode.allCases, id: \.self) { mode in
+                    Button {
+                        withAnimation(.spring(response: 0.25, dampingFraction: 0.8)) {
+                            store.appearanceMode = mode
+                        }
+                    } label: {
+                        let selected = store.appearanceMode == mode
+                        HStack(spacing: 5) {
+                            Image(systemName: mode.icon)
+                                .font(.system(size: 12, weight: selected ? .semibold : .regular))
+                            Text(mode.label)
+                                .font(.system(size: 12, weight: selected ? .semibold : .regular))
+                        }
+                        .foregroundStyle(selected ? AppTheme.ink : AppTheme.inkTertiary)
+                        .frame(maxWidth: .infinity)
+                        .padding(.vertical, 9)
+                        .background(
+                            RoundedRectangle(cornerRadius: 8, style: .continuous)
+                                .fill(selected ? AppTheme.surfaceRaised : Color.clear)
+                                .shadow(color: selected ? .black.opacity(0.08) : .clear,
+                                        radius: 4, x: 0, y: 1)
+                        )
+                    }
+                    .buttonStyle(PlainButtonStyle())
+                }
+            }
+            .padding(3)
+            .background(AppTheme.surfaceSunken)
+            .clipShape(RoundedRectangle(cornerRadius: 11, style: .continuous))
+        }
+    }
+
     // MARK: — Media
 
     private var mediaSection: some View {
@@ -49,7 +89,7 @@ struct SettingsView: View {
                           subtitle: "Skip files already on NAS",
                           isOn: $store.backupFilter.newFilesOnly)
             }
-            .background(Color.white)
+            .background(AppTheme.surfaceRaised)
             .clipShape(RoundedRectangle(cornerRadius: AppTheme.radius, style: .continuous))
             .shadow(color: AppTheme.cardShadow, radius: 12, x: 0, y: 2)
         }
@@ -78,7 +118,7 @@ struct SettingsView: View {
                           subtitle: "Preserve battery on large libraries",
                           isOn: $store.chargingOnlyMode)
             }
-            .background(Color.white)
+            .background(AppTheme.surfaceRaised)
             .clipShape(RoundedRectangle(cornerRadius: AppTheme.radius, style: .continuous))
             .shadow(color: AppTheme.cardShadow, radius: 12, x: 0, y: 2)
             .animation(.spring(response: 0.3, dampingFraction: 0.8), value: store.quietHoursEnabled)
@@ -135,7 +175,7 @@ struct SettingsView: View {
                     .padding(.vertical, 10)
                 }
             }
-            .background(Color.white)
+            .background(AppTheme.surfaceRaised)
             .clipShape(RoundedRectangle(cornerRadius: AppTheme.radius, style: .continuous))
             .shadow(color: AppTheme.cardShadow, radius: 12, x: 0, y: 2)
             .animation(.spring(response: 0.3, dampingFraction: 0.8), value: lanMonitor.isOnCellular)
@@ -206,13 +246,15 @@ struct SettingsView: View {
                                     .clipShape(RoundedRectangle(cornerRadius: 6, style: .continuous))
                             }
                             .buttonStyle(ScaleButtonStyle())
+                            .accessibilityLabel("Open Tailscale app")
+                            .accessibilityHint("Opens the Tailscale app to connect the VPN")
                         }
                     }
                     .padding(.horizontal, AppTheme.cardPad)
                     .padding(.vertical, 12)
                 }
             }
-            .background(Color.white)
+            .background(AppTheme.surfaceRaised)
             .clipShape(RoundedRectangle(cornerRadius: AppTheme.radius, style: .continuous))
             .shadow(color: AppTheme.cardShadow, radius: 12, x: 0, y: 2)
             .animation(.spring(response: 0.3, dampingFraction: 0.8), value: store.useTailscaleWhenRemote)
@@ -233,7 +275,7 @@ struct SettingsView: View {
                 hairline
                 notifRow(icon: "exclamationmark.triangle", title: "On errors", value: "On")
             }
-            .background(Color.white)
+            .background(AppTheme.surfaceRaised)
             .clipShape(RoundedRectangle(cornerRadius: AppTheme.radius, style: .continuous))
             .shadow(color: AppTheme.cardShadow, radius: 12, x: 0, y: 2)
         }