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/Browse/BrowseView.swift

@@ -15,7 +15,7 @@ struct BrowseView: View {
     var body: some View {
         NavigationStack {
             ZStack {
-                Color.white.ignoresSafeArea()
+                AppTheme.background.ignoresSafeArea()
 
                 VStack(spacing: 0) {
                     // Path bar
@@ -40,21 +40,31 @@ struct BrowseView: View {
 
                     if isLoading {
                         Spacer()
-                        ProgressView()
-                            .tint(AppTheme.inkTertiary)
+                        VStack(spacing: 10) {
+                            ProgressView()
+                                .tint(AppTheme.inkTertiary)
+                            Text("Loading…")
+                                .font(AppTheme.caption())
+                                .foregroundStyle(AppTheme.inkTertiary)
+                        }
                         Spacer()
                     } else if let error {
                         Spacer()
                         VStack(spacing: 12) {
                             Image(systemName: "exclamationmark.triangle")
-                                .font(.system(size: 28, weight: .light))
+                                .font(.system(size: 28, weight: .ultraLight))
                                 .foregroundStyle(AppTheme.inkQuaternary)
-                            Text(error)
-                                .font(AppTheme.caption())
-                                .foregroundStyle(AppTheme.inkSecondary)
-                                .multilineTextAlignment(.center)
+                            VStack(spacing: 4) {
+                                Text("Could not load folder")
+                                    .font(.system(size: 14, weight: .medium))
+                                    .foregroundStyle(AppTheme.inkSecondary)
+                                Text(error)
+                                    .font(AppTheme.caption())
+                                    .foregroundStyle(AppTheme.inkTertiary)
+                                    .multilineTextAlignment(.center)
+                            }
                         }
-                        .padding()
+                        .padding(.horizontal, 32)
                         Spacer()
                     } else {
                         List {