refactor: change singleton registrations to lazy singleton for improved performance

.agents/skills/krow-mobile-architecture/SKILL.md

@@ -666,17 +666,17 @@ class StaffConnectorRepositoryImpl implements StaffConnectorRepository {
 class StaffMainModule extends Module {
   @override
   void binds(Injector i) {
-    i.addSingleton<StaffConnectorRepository>(
+    i.addLazySingleton<StaffConnectorRepository>(
       StaffConnectorRepositoryImpl.new,
     );
     
-    i.addSingleton(
+    i.addLazySingleton(
       () => GetProfileCompletionUseCase(
         repository: i.get<StaffConnectorRepository>(),
       ),
     );
     
-    i.addSingleton(
+    i.addLazySingleton(
       () => StaffMainCubit(
         getProfileCompletionUsecase: i.get(),
       ),
@@ -772,7 +772,7 @@ StateError: Cannot emit new states after calling close
 
 ```dart
 // ✅ GOOD: Singleton registration
-i.addSingleton<ProfileCubit>(
+i.addLazySingleton<ProfileCubit>(
   () => ProfileCubit(useCase1, useCase2),
 );