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/Connect/ConnectViewModel.swift

@@ -24,6 +24,11 @@ final class ConnectViewModel: ObservableObject {
     }
 
     func verify() async {
+        let service: any NASTransferProtocol = selectedProtocol == .smb ? SMBService() : SFTPService()
+        await verifyWith(transfer: service)
+    }
+
+    func verifyWith(transfer: any NASTransferProtocol) async {
         isVerifying = true
         isConnected = false
         verifyError = nil
@@ -36,11 +41,10 @@ final class ConnectViewModel: ObservableObject {
             remotePath: remotePath
         )
 
-        let service: any NASTransferProtocol = selectedProtocol == .smb ? SMBService() : SFTPService()
         do {
-            try await service.connect(to: connection.host, port: connection.port,
-                                      username: connection.username, password: connection.password)
-            service.disconnect()
+            try await transfer.connect(to: connection.host, port: connection.port,
+                                       username: connection.username, password: connection.password)
+            transfer.disconnect()
             isConnected = true
             ConnectionStore.shared.savedConnection = connection
         } catch let e as BackupError {