Remote sync of webdav

pubspec.yaml

@@ -74,6 +74,22 @@ dependencies:
   # Local SQLite database
   sqflite: ^2.4.1
 
+  # Browser-based OAuth2 (PKCE) redirect capture for Dropbox/OneDrive —
+  # unlike Google, neither has an official Flutter sign-in package.
+  flutter_web_auth_2: ^4.1.0
+
+  # PKCE code_verifier/code_challenge generation (SHA-256 + base64url)
+  crypto: ^3.0.5
+
+  # WebDAV multistatus (PROPFIND) response parsing — for self-hosted
+  # personal cloud servers (Nextcloud, ownCloud, a bare Apache/nginx WebDAV
+  # server, etc).
+  xml: ^6.6.1
+
+  # OS-backed encrypted storage (Keystore/Keychain) for WebDAV credentials,
+  # so sign-in survives a cold app restart instead of living in memory only.
+  flutter_secure_storage: ^10.0.0
+
 dev_dependencies:
   flutter_test:
     sdk: flutter
@@ -82,6 +98,15 @@ dev_dependencies:
   # can be unit tested on the Dart VM, without a real Android/iOS device.
   sqflite_common_ffi: ^2.3.4+4
 
+  # Platform-interface for faking FlutterSecureStoragePlatform.instance in
+  # webdav_provider_credentials_test.dart, same pattern as faking
+  # PathProviderPlatform.instance elsewhere.
+  flutter_secure_storage_platform_interface: ^2.0.3
+
+  # For faking PathProviderPlatform in cloud_sync_service_test.dart
+  path_provider_platform_interface: ^2.1.2
+  plugin_platform_interface: ^2.1.8
+
   # The "flutter_lints" package below contains a set of recommended lints to
   # encourage good coding practices. The lint set provided by the package is
   # activated in the `analysis_options.yaml` file located at the root of your