Add explicit types and improve type safety across codebase

This commit adds explicit type annotations to variables, function parameters, and return types throughout the codebase, particularly in widget trees, Bloc logic, and repository implementations. The changes improve code readability, maintainability, and type safety, and align with Dart best practices. No business logic was changed.

apps/mobile/packages/core/lib/src/domain/arguments/usecase_argument.dart

@@ -8,5 +8,5 @@ abstract class UseCaseArgument extends Equatable {
   const UseCaseArgument();
 
   @override
-  List<Object?> get props => [];
+  List<Object?> get props => <Object?>[];
 }