feat(security): implementado servicio de CustomUserDetailsService

src/main/java/com/example/apprecetas/security/service/CustomUserDetailsServiceImpl.java

+package com.example.apprecetas.security.service;
+
+import com.example.apprecetas.user.domain.repository.ReadUserRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.security.core.userdetails.User;
+import org.springframework.security.core.userdetails.UserDetails;
+import org.springframework.security.core.userdetails.UserDetailsService;
+import org.springframework.security.core.userdetails.UsernameNotFoundException;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+public class CustomUserDetailsServiceImpl implements UserDetailsService {
+
+    private final ReadUserRepository userRepository;
+
+    @Override
+    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
+        return userRepository.readByUsername(username)
+                .map(user -> User.withUsername(user.getUsername())
+                        .password(user.getPassword())
+                        .roles(user.getRole().name())
+                        .build())
+                .orElseThrow(() -> new UsernameNotFoundException("User con username " + username + " no encontrado"));
+    }
+}