Move apps to mobile directory structure

Relocated all app directories (client, design_system_viewer, staff) and their contents under the new 'apps/mobile' path. This change improves project organization and prepares for future platform-specific structuring.

apps/mobile/packages/features/client/authentication/pubspec.yaml

@@ -0,0 +1,35 @@
+name: client_authentication
+description: Client Authentication and Registration feature.
+version: 0.0.1
+publish_to: none
+resolution: workspace
+
+environment:
+  sdk: '>=3.10.0 <4.0.0'
+  flutter: ">=3.0.0"
+
+dependencies:
+  flutter:
+    sdk: flutter
+  flutter_bloc: ^8.1.0
+  flutter_modular: ^6.3.0
+  equatable: ^2.0.5
+  firebase_core: ^4.2.1
+  firebase_auth: ^6.1.2 # Updated for compatibility
+  firebase_data_connect: ^0.2.2+1
+  
+  # Architecture Packages
+  design_system:
+    path: ../../../../design_system
+  core_localization:
+    path: ../../../core_localization
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+  bloc_test: ^9.1.0
+  mocktail: ^1.0.0
+  build_runner: ^2.4.15
+
+flutter:
+  uses-material-design: true