Fix mapper + DTO

src/main/java/com/faf223/expensetrackerfaf/repository/ExpenseRepository.java

@@ -1,6 +1,7 @@
 package com.faf223.expensetrackerfaf.repository;
 
 import com.faf223.expensetrackerfaf.model.Expense;
+import com.faf223.expensetrackerfaf.model.User;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.stereotype.Repository;
 
@@ -8,5 +9,5 @@ import java.util.List;
 
 @Repository
 public interface ExpenseRepository extends JpaRepository<Expense, Long> {
-    List<Expense> findByUserUuid(String userUuid);
+    List<Expense> findByUser(User user);
 }

src/main/java/com/faf223/expensetrackerfaf/repository/IncomeRepository.java

@@ -1,6 +1,7 @@
 package com.faf223.expensetrackerfaf.repository;
 
 import com.faf223.expensetrackerfaf.model.Income;
+import com.faf223.expensetrackerfaf.model.User;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.stereotype.Repository;
 
@@ -8,5 +9,5 @@ import java.util.List;
 
 @Repository
 public interface IncomeRepository extends JpaRepository<Income, Long> {
-    List<Income> findByUserUuid(String userUuid);
+    List<Income> findByUser(User user);
 }

src/main/java/com/faf223/expensetrackerfaf/repository/UserRepository.java

@@ -3,5 +3,8 @@ package com.faf223.expensetrackerfaf.repository;
 import com.faf223.expensetrackerfaf.model.User;
 import org.springframework.data.jpa.repository.JpaRepository;
 
+import java.util.Optional;
+
 public interface UserRepository extends JpaRepository<User, String> {
+    Optional<User> getUserByUserUuid(String userUuid);
 }