feat(staff): implement staff home screen shell (staff_main)

- Created staff_main package structure
- Implemented StaffMainPage, StaffMainBottomBar, StaffMainCubit
- Added localization for staff_main tabs
- Added typed navigation extension
- Registered package in workspace

apps/mobile/packages/features/staff/staff_main/pubspec.yaml

@@ -0,0 +1,43 @@
+name: staff_main
+description: Main shell and navigation for the staff application.
+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
+  lucide_icons: ^0.257.0
+  
+  # Architecture Packages
+  design_system:
+    path: ../../../design_system
+  core_localization:
+    path: ../../../core_localization
+
+  # Features (Commented out until they are ready)
+  # staff_home:
+  #   path: ../home
+  # staff_shifts:
+  #   path: ../shifts
+  # staff_payments:
+  #   path: ../payments
+  # staff_profile:
+  #   path: ../profile
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+  bloc_test: ^9.1.0
+  mocktail: ^1.0.0
+  flutter_lints: ^6.0.0
+
+flutter:
+  uses-material-design: true