chore: enforce coding standards and add project guidelines

- Replace JPQL queries in TaskRepositoryImpl with Panache shorthand and Java filtering
- Replace == null / != null with Objects.isNull() / Objects.nonNull() across all layers
- Add CLAUDE.md with project conventions, architecture rules, and coding standards
- Add .github/PULL_REQUEST_TEMPLATE.md for standardized PR descriptions in Portuguese
- Add .claude/skills/new-task.md workflow guide (issue reading → branch → commit → PR)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.claude/skills/new-task.md

@@ -0,0 +1,92 @@
+---
+trigger: manual
+description: Workflow completo para iniciar e concluir uma nova tarefa a partir de uma issue do GitHub
+---
+
+# Workflow de Nova Tarefa
+
+Siga estes passos em ordem para executar uma tarefa do início ao PR.
+
+## Passo 1 — Ler a issue
+
+```bash
+gh issue view <número> --repo <owner/repo>
+```
+
+Leia o **título** e a **descrição** completa da issue antes de qualquer ação.
+
+## Passo 2 — Criar a branch
+
+Escolha o prefixo de acordo com o tipo de mudança:
+
+| Tipo | Prefixo | Quando usar |
+|------|---------|-------------|
+| Nova funcionalidade | `feat/` | Algo novo que o usuário percebe |
+| Correção de bug | `fix/` | Comportamento errado corrigido |
+| Manutenção/chore | `chore/` | Refactor, config, padrões, docs |
+| Teste | `test/` | Apenas adição/correção de testes |
+
+Formato do nome: `<prefixo><descricao-em-kebab-case>`
+
+```bash
+git checkout main
+git pull origin main
+git checkout -b feat/nome-descritivo-da-tarefa
+```
+
+## Passo 3 — Executar a tarefa
+
+Implemente as mudanças seguindo os padrões definidos no `CLAUDE.md` do projeto.
+
+Lembre-se de:
+- Não usar SQL nativo nem JPQL nas repositories
+- Usar `Objects.isNull()` / `Objects.nonNull()` ao invés de `== null` / `!= null`
+- Seguir a Clean Architecture (entities → use cases → interface adapters → frameworks)
+- Não importar frameworks nas camadas de domínio
+
+## Passo 4 — Commit
+
+Formato obrigatório: `<tipo>: <descrição em inglês no imperativo>`
+
+```bash
+git add <arquivos específicos>
+git commit -m "feat: add null check using Objects utility methods"
+```
+
+Tipos válidos: `feat`, `fix`, `chore`, `docs`, `test`, `refactor`
+
+Exemplos:
+- `feat: add task filtering by organization`
+- `fix: prevent duplicate user organization entries`
+- `chore: replace JPQL queries with Panache shorthand`
+
+## Passo 5 — Criar o Pull Request
+
+```bash
+git push origin <nome-da-branch>
+gh pr create \
+  --title "<tipo>: <descrição curta em inglês>" \
+  --body "$(cat <<'EOF'
+## Descrição
+...
+
+## Tipo de mudança
+- [x] Nova funcionalidade
+
+## Issue relacionada
+Fecha #<número>
+
+## O que foi feito
+- ...
+
+## Como testar
+1. ...
+
+## Checklist
+- [x] Código segue padrões do projeto
+- [x] Build passa sem erros
+EOF
+)"
+```
+
+A descrição do PR deve ser **em português**, detalhada e seguir o template em `.github/PULL_REQUEST_TEMPLATE.md`.

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,38 @@
+## Descrição
+
+<!-- Descreva de forma clara e objetiva o que foi implementado, corrigido ou alterado neste PR. -->
+
+## Tipo de mudança
+
+- [ ] Nova funcionalidade (`feat`)
+- [ ] Correção de bug (`fix`)
+- [ ] Melhoria/refatoração (`chore`)
+- [ ] Documentação (`docs`)
+- [ ] Testes (`test`)
+
+## Issue relacionada
+
+Fecha #<!-- número da issue -->
+
+## O que foi feito
+
+<!-- Liste as principais mudanças realizadas: -->
+
+-
+-
+-
+
+## Como testar
+
+<!-- Descreva o passo a passo para validar as mudanças: -->
+
+1.
+2.
+3.
+
+## Checklist
+
+- [ ] O código segue os padrões do projeto (sem SQL nativo, sem JPQL direto, usando `Objects.isNull`/`nonNull`)
+- [ ] Foram criados/atualizados testes para as mudanças
+- [ ] O build passa sem erros (`./mvnw verify` ou `quarkus dev`)
+- [ ] Foi revisado o impacto em outras partes do sistema

CLAUDE.md

@@ -0,0 +1,145 @@
+# Bee Task — Guia de Desenvolvimento
+
+## Stack
+
+- **Backend**: Quarkus + Hibernate ORM + Panache (Java 17+)
+- **Frontend**: React + TypeScript + Tailwind CSS
+- **Banco de dados**: PostgreSQL (via Docker Compose)
+
+## Arquitetura
+
+O backend segue **Clean Architecture** adaptada:
+
+```
+entities/          → Domínio puro: entidades e regras de negócio
+usecase/           → Casos de uso: orquestram entidades e repositórios (interfaces)
+interfaceadapters/ → Controllers REST (JAX-RS), mappers de entrada/saída
+frameworks/        → Implementações: Panache repositories, JPA entities, mappers de persistência
+```
+
+**Regras de dependência (nunca viole):**
+- `entities` não importa nada externo (sem frameworks, sem Jakarta, sem Quarkus)
+- `usecase` só importa `entities` e interfaces próprias
+- `interfaceadapters` importa `usecase` e `entities`, nunca `frameworks`
+- `frameworks` implementa as interfaces de `usecase`
+
+## Padrões de Código Java
+
+### Repositories — Sem SQL nativo e sem JPQL explícito
+
+Nas implementações de repository (`frameworks/persistence/repository/`), use **sempre** o estilo shorthand do Panache:
+
+```java
+// CORRETO — shorthand Panache (propriedades da entidade)
+find("user.email = ?1 and status = ?2", email, status).list();
+find("organization.id", organizationId).stream().toList();
+findByIdOptional(id).map(mapper::toDomain);
+
+// ERRADO — JPQL explícito
+find("SELECT t FROM TaskEntity t WHERE t.user.email = ?1", email);
+find("select distinct t from TaskEntity t join t.history h where ...", ...);
+
+// ERRADO — SQL nativo
+getEntityManager().createNativeQuery("SELECT * FROM tasks WHERE ...");
+```
+
+Para consultas complexas que envolvem JOINs com coleções, prefira buscar via shorthand e filtrar em Java:
+
+```java
+// Busca por propriedade simples + filtragem em Java
+return find("user.email = ?1", email).list().stream()
+    .filter(entity -> entity.getHistory().stream().anyMatch(h ->
+        Objects.nonNull(h.getStartAt()) &&
+        !h.getStartAt().isAfter(end) &&
+        (Objects.isNull(h.getEndAt()) || !h.getEndAt().isBefore(start))))
+    .map(mapper::toDomain)
+    .toList();
+```
+
+### Verificações de nulo — `Objects.isNull` e `Objects.nonNull`
+
+Use sempre `Objects.isNull(x)` e `Objects.nonNull(x)` ao invés dos operadores `== null` e `!= null`:
+
+```java
+// CORRETO
+if (Objects.isNull(entity.getId())) {
+    persist(entity);
+}
+
+if (Objects.nonNull(input.projectId())) {
+    task.setProject(projectRepository.findProjectById(input.projectId()).orElseThrow());
+}
+
+// ERRADO
+if (entity.getId() == null) { ... }
+if (input.projectId() != null) { ... }
+```
+
+Isso se aplica a: repositories, mappers, use cases e entities.  
+Exceção tolerada: ternários simples inline onde a legibilidade é melhor com `!=`.
+
+### Mappers de persistência
+
+Sempre verifique nulo na entrada de métodos de mapeamento:
+
+```java
+public static MyEntity toEntity(MyDomain domain) {
+    if (Objects.isNull(domain)) return null;
+    // ...
+}
+```
+
+### Padrão de save nos repositories
+
+```java
+if (Objects.isNull(entity.getId())) {
+    persist(entity);
+} else {
+    entity = getEntityManager().merge(entity);
+}
+```
+
+## Workflow de Tarefas
+
+Use o skill `/new-task` para seguir o guia completo de início ao PR.
+
+### Branches
+
+| Tipo | Prefixo |
+|------|---------|
+| Funcionalidade | `feat/` |
+| Bug | `fix/` |
+| Manutenção | `chore/` |
+| Testes | `test/` |
+
+### Commits
+
+Formato: `<tipo>: <descrição em inglês no imperativo>`
+
+```
+feat: add task filtering by user organization
+fix: prevent null pointer in task history mapper
+chore: replace JPQL with Panache shorthand queries
+```
+
+### Pull Requests
+
+- Título em inglês, curto (< 70 chars)
+- Descrição em **português**, seguindo `.github/PULL_REQUEST_TEMPLATE.md`
+- Vincular a issue com `Fecha #<número>`
+
+## Rodando o projeto
+
+```bash
+# Backend
+cd backend
+./mvnw quarkus:dev
+
+# Frontend
+cd frontend
+npm install
+npm run dev
+
+# Banco de dados
+docker-compose up -d
+```

backend/src/main/java/net/beetechgroup/beetask/entities/Project.java

@@ -1,6 +1,7 @@
 package net.beetechgroup.beetask.entities;
 
 import java.util.List;
+import java.util.Objects;
 
 import net.beetechgroup.beetask.entities.organization.Organization;
 
@@ -47,7 +48,7 @@ public class Project {
         return "Project{" +
                 "id=" + id +
                 ", name='" + name + '\'' +
-                ", organization=" + (organization != null ? organization.getName() : "null") +
+                ", organization=" + (Objects.nonNull(organization) ? organization.getName() : "null") +
                 '}';
     }
 }

backend/src/main/java/net/beetechgroup/beetask/entities/task/Task.java

@@ -3,6 +3,7 @@ package net.beetechgroup.beetask.entities.task;
 import java.time.LocalDateTime;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 
 import net.beetechgroup.beetask.entities.Project;
 import net.beetechgroup.beetask.entities.User;
@@ -48,9 +49,6 @@ public class Task {
     public void setStatus(TaskStatus status) {
         if (this.status == status) return;
 
-        // Note: Automatic start/stop removed from setStatus to avoid 
-        // compilation errors and ensure user attribution via StartTaskUseCase.
-        
         if (status == TaskStatus.COMPLETED) {
             this.finishedAt = LocalDateTime.now();
         } else {
@@ -106,7 +104,7 @@ public class Task {
     public void start() {
         TaskHistoryItem current = getCurrentRunningItem();
 
-        if (current != null) {
+        if (Objects.nonNull(current)) {
             throw new IllegalStateException("Tarefa já está em execução");
         }
 
@@ -119,12 +117,10 @@ public class Task {
     public void stop() {
         TaskHistoryItem current = getCurrentRunningItem();
 
-    if (current == null) {
+        if (Objects.isNull(current)) {
             throw new IllegalStateException("Task não está em execução");
         }
 
         current.setEndAt(LocalDateTime.now());
     }
-
-
 }

backend/src/main/java/net/beetechgroup/beetask/entities/task/TaskHistoryItem.java

@@ -1,6 +1,7 @@
 package net.beetechgroup.beetask.entities.task;
 
 import java.time.LocalDateTime;
+import java.util.Objects;
 
 public class TaskHistoryItem {
     private Long id;
@@ -32,6 +33,6 @@ public class TaskHistoryItem {
     }
 
     public boolean isRunning() {
-        return endAt == null;
+        return Objects.isNull(endAt);
     }
 }

backend/src/main/java/net/beetechgroup/beetask/frameworks/persistence/mapper/OrganizationEntityMapper.java

@@ -1,5 +1,6 @@
 package net.beetechgroup.beetask.frameworks.persistence.mapper;
 
+import java.util.Objects;
 import net.beetechgroup.beetask.entities.organization.Organization;
 import net.beetechgroup.beetask.frameworks.persistence.entities.OrganizationEntity;
 
@@ -12,7 +13,7 @@ public class OrganizationEntityMapper {
     }
 
     public static Organization toDomain(OrganizationEntity entity) {
-        if (entity == null) return null;
+        if (Objects.isNull(entity)) return null;
 
         Organization organization = new Organization();
         organization.setId(entity.getId());

backend/src/main/java/net/beetechgroup/beetask/frameworks/persistence/mapper/ProjectEntityMapper.java

@@ -1,12 +1,13 @@
 package net.beetechgroup.beetask.frameworks.persistence.mapper;
 
+import java.util.Objects;
 import net.beetechgroup.beetask.entities.Project;
 import net.beetechgroup.beetask.frameworks.persistence.entities.ProjectEntity;
 
 public class ProjectEntityMapper {
 
     public static ProjectEntity toEntity(Project project) {
-        if (project == null) return null;
+        if (Objects.isNull(project)) return null;
         ProjectEntity entity = new ProjectEntity();
         entity.setId(project.getId());
         entity.setName(project.getName());
@@ -15,7 +16,7 @@ public class ProjectEntityMapper {
     }
 
     public static Project toDomain(ProjectEntity entity) {
-        if (entity == null) return null;
+        if (Objects.isNull(entity)) return null;
 
         Project project = new Project();
         project.setId(entity.getId());

backend/src/main/java/net/beetechgroup/beetask/frameworks/persistence/mapper/TaskEntityMapper.java

@@ -1,6 +1,7 @@
 package net.beetechgroup.beetask.frameworks.persistence.mapper;
 
 import java.util.ArrayList;
+import java.util.Objects;
 
 import net.beetechgroup.beetask.entities.task.Task;
 import net.beetechgroup.beetask.frameworks.persistence.entities.TaskEntity;
@@ -26,7 +27,7 @@ public class TaskEntityMapper {
     }
 
     public static Task toDomain(TaskEntity entity) {
-        if (entity == null) return null;
+        if (Objects.isNull(entity)) return null;
 
         Task task = new Task();
         task.setId(entity.getId());

backend/src/main/java/net/beetechgroup/beetask/frameworks/persistence/mapper/TaskHistoryItemMapper.java

@@ -1,5 +1,6 @@
 package net.beetechgroup.beetask.frameworks.persistence.mapper;
 
+import java.util.Objects;
 import net.beetechgroup.beetask.entities.task.TaskHistoryItem;
 import net.beetechgroup.beetask.frameworks.persistence.entities.TaskHistoryItemEntity;
 
@@ -13,7 +14,7 @@ public class TaskHistoryItemMapper {
     }
 
     public static TaskHistoryItem toDomain(TaskHistoryItemEntity entity) {
-        if (entity == null) return null;
+        if (Objects.isNull(entity)) return null;
 
         TaskHistoryItem item = new TaskHistoryItem();
         item.setId(entity.getId());

backend/src/main/java/net/beetechgroup/beetask/frameworks/persistence/mapper/UserEntityMapper.java

@@ -1,12 +1,13 @@
 package net.beetechgroup.beetask.frameworks.persistence.mapper;
 
+import java.util.Objects;
 import net.beetechgroup.beetask.entities.User;
 import net.beetechgroup.beetask.frameworks.persistence.entities.UserEntity;
 
 public class UserEntityMapper {
 
     public static UserEntity toEntity(User user) {
-        if (user == null) return null;
+        if (Objects.isNull(user)) return null;
         UserEntity entity = new UserEntity();
         entity.setId(user.getId());
         entity.setName(user.getName());
@@ -17,7 +18,7 @@ public class UserEntityMapper {
     }
 
     public static User toDomain(UserEntity entity) {
-        if (entity == null) return null;
+        if (Objects.isNull(entity)) return null;
         User user = new User();
         user.setId(entity.getId());
         user.setName(entity.getName());

backend/src/main/java/net/beetechgroup/beetask/frameworks/persistence/mapper/UserOrganizationEntityMapper.java

@@ -1,12 +1,13 @@
 package net.beetechgroup.beetask.frameworks.persistence.mapper;
 
+import java.util.Objects;
 import net.beetechgroup.beetask.entities.organization.UserOrganization;
 import net.beetechgroup.beetask.frameworks.persistence.entities.UserOrganizationEntity;
 
 public class UserOrganizationEntityMapper {
 
     public static UserOrganization toDomain(UserOrganizationEntity entity) {
-        if (entity == null) return null;
+        if (Objects.isNull(entity)) return null;
         UserOrganization domain = new UserOrganization();
         domain.setUser(UserEntityMapper.toDomain(entity.getUser()));
         domain.setOrganization(OrganizationEntityMapper.toDomain(entity.getOrganization()));
@@ -16,7 +17,7 @@ public class UserOrganizationEntityMapper {
     }
 
     public static UserOrganizationEntity toEntity(UserOrganization domain) {
-        if (domain == null) return null;
+        if (Objects.isNull(domain)) return null;
         UserOrganizationEntity entity = new UserOrganizationEntity();
         entity.setUser(UserEntityMapper.toEntity(domain.getUser()));
         entity.setOrganization(OrganizationEntityMapper.toEntity(domain.getOrganization()));

backend/src/main/java/net/beetechgroup/beetask/frameworks/persistence/repository/OrganizationRepositoryImpl.java

@@ -19,7 +19,7 @@ public class OrganizationRepositoryImpl implements OrganizationRepository, Panac
     @Transactional
     public Organization saveOrganization(Organization organization) {
         OrganizationEntity entity = OrganizationEntityMapper.toEntity(organization);
-        if (entity.getId() == null) {
+        if (Objects.isNull(entity.getId())) {
             persist(entity);
         } else {
             entity = getEntityManager().merge(entity);

backend/src/main/java/net/beetechgroup/beetask/frameworks/persistence/repository/ProjectRepositoryImpl.java

@@ -9,6 +9,7 @@ import net.beetechgroup.beetask.frameworks.persistence.mapper.ProjectEntityMappe
 import net.beetechgroup.beetask.usecase.repository.ProjectRepository;
 
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 
 @ApplicationScoped
@@ -18,7 +19,7 @@ public class ProjectRepositoryImpl implements ProjectRepository, PanacheReposito
     @Transactional
     public Project saveProject(Project project) {
         ProjectEntity entity = ProjectEntityMapper.toEntity(project);
-        if (entity.getId() == null) {
+        if (Objects.isNull(entity.getId())) {
             persist(entity);
         } else {
             entity = getEntityManager().merge(entity);

backend/src/main/java/net/beetechgroup/beetask/frameworks/persistence/repository/TaskRepositoryImpl.java

@@ -1,12 +1,14 @@
 package net.beetechgroup.beetask.frameworks.persistence.repository;
 
 import java.util.List;
+import java.util.Objects;
 import java.time.LocalDateTime;
 
 import io.quarkus.hibernate.orm.panache.PanacheRepository;
 import jakarta.enterprise.context.ApplicationScoped;
 import jakarta.transaction.Transactional;
 import net.beetechgroup.beetask.entities.task.Task;
+import net.beetechgroup.beetask.entities.task.TaskStatus;
 import net.beetechgroup.beetask.frameworks.persistence.entities.TaskEntity;
 import net.beetechgroup.beetask.frameworks.persistence.mapper.TaskEntityMapper;
 import net.beetechgroup.beetask.usecase.exceptions.TaskNotFoundException;
@@ -19,7 +21,7 @@ public class TaskRepositoryImpl implements TaskRepository, PanacheRepository<Tas
     @Transactional
     public Task saveTask(Task task) {
         TaskEntity entity = TaskEntityMapper.toEntity(task);
-        if (entity.getId() == null) {
+        if (Objects.isNull(entity.getId())) {
             persist(entity);
         } else {
             entity = getEntityManager().merge(entity);
@@ -41,17 +43,20 @@ public class TaskRepositoryImpl implements TaskRepository, PanacheRepository<Tas
 
     @Override
     public List<Task> findTasksWorkedByUserInPeriod(String email, LocalDateTime start, LocalDateTime end) {
-        return find("select distinct t from TaskEntity t join t.history h where t.user.email = ?1 " +
+        return find("user.email = ?1", email).list().stream()
-                "and h.startAt <= ?3 and (h.endAt is null or h.endAt >= ?2)",
+                .filter(entity -> entity.getHistory().stream().anyMatch(h ->
-                email, start, end).list().stream().map(TaskEntityMapper::toDomain).toList();
+                        Objects.nonNull(h.getStartAt()) &&
+                        !h.getStartAt().isAfter(end) &&
+                        (Objects.isNull(h.getEndAt()) || !h.getEndAt().isBefore(start))))
+                .map(TaskEntityMapper::toDomain)
+                .toList();
     }
 
     @Override
     public List<Task> findTasksFinishedByUserInPeriod(String email, LocalDateTime start, LocalDateTime end) {
-        return find("select distinct t from TaskEntity t where t.user.email = ?1 " +
+        return find("user.email = ?1 and status = ?2 and finishedAt >= ?3 and finishedAt <= ?4",
-                "and t.status = net.beetechgroup.beetask.entities.task.TaskStatus.COMPLETED " +
+                email, TaskStatus.COMPLETED, start, end)
-                "and t.finishedAt >= ?2 and t.finishedAt <= ?3",
+                .list().stream().map(TaskEntityMapper::toDomain).toList();
-                email, start, end).list().stream().map(TaskEntityMapper::toDomain).toList();
     }
 
     @Override

backend/src/main/java/net/beetechgroup/beetask/frameworks/persistence/repository/UserOrganizationRepositoryImpl.java

@@ -10,6 +10,7 @@ import net.beetechgroup.beetask.frameworks.persistence.mapper.UserOrganizationEn
 import net.beetechgroup.beetask.usecase.repository.UserOrganizationRepository;
 
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 
 @ApplicationScoped
@@ -47,8 +48,7 @@ public class UserOrganizationRepositoryImpl implements UserOrganizationRepositor
     @Transactional
     public void save(UserOrganization userOrganization) {
         UserOrganizationEntity entity = UserOrganizationEntityMapper.toEntity(userOrganization);
-        if (entity.getUser().getId() != null && entity.getOrganization().getId() != null) {
+        if (Objects.nonNull(entity.getUser().getId()) && Objects.nonNull(entity.getOrganization().getId())) {
-            // Find existing by user and org to update instead of creating new if it exists
             Optional<UserOrganizationEntity> existing = find("user.id = ?1 and organization.id = ?2",
                 entity.getUser().getId(), entity.getOrganization().getId()).firstResultOptional();
             if (existing.isPresent()) {

backend/src/main/java/net/beetechgroup/beetask/frameworks/persistence/repository/UserRepositoryImpl.java

@@ -4,6 +4,7 @@ import io.quarkus.hibernate.orm.panache.PanacheRepository;
 import jakarta.enterprise.context.ApplicationScoped;
 import jakarta.inject.Inject;
 import jakarta.transaction.Transactional;
+import java.util.Objects;
 import net.beetechgroup.beetask.entities.User;
 import net.beetechgroup.beetask.frameworks.persistence.entities.UserEntity;
 import net.beetechgroup.beetask.frameworks.persistence.mapper.UserEntityMapper;
@@ -25,7 +26,7 @@ public class UserRepositoryImpl implements UserRepository, PanacheRepository<Use
     @Transactional
     public User save(User user) {
         UserEntity entity = UserEntityMapper.toEntity(user);
-        if (entity.getId() == null) {
+        if (Objects.isNull(entity.getId())) {
             persist(entity);
         } else {
             entity = getEntityManager().merge(entity);

backend/src/main/java/net/beetechgroup/beetask/interfaceadapters/controllers/task/TaskControllerMapper.java

@@ -1,5 +1,6 @@
 package net.beetechgroup.beetask.interfaceadapters.controllers.task;
 
+import java.util.Objects;
 import net.beetechgroup.beetask.usecase.task.create.CreateTaskInput;
 import net.beetechgroup.beetask.usecase.task.create.CreateTaskOutput;
 import net.beetechgroup.beetask.usecase.task.start.StartTaskInput;
@@ -47,7 +48,7 @@ public class TaskControllerMapper {
                 request.status(),
                 request.projectId(),
                 userEmail,
-                request.history() != null ? request.history().stream()
+                Objects.nonNull(request.history()) ? request.history().stream()
                         .map(h -> new TaskHistoryItemInput(h.id(), h.startAt(), h.endAt()))
                         .toList() : null
         );

backend/src/main/java/net/beetechgroup/beetask/usecase/auth/login/LoginUseCase.java

@@ -8,6 +8,7 @@ import net.beetechgroup.beetask.usecase.repository.UserRepository;
 import java.time.LocalDateTime;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
@@ -69,7 +70,7 @@ public class LoginUseCase {
         return new LoginOutput(
                 user.getName(),
                 user.getEmail(),
-                user.getPhoto() != null ? user.getPhoto() : "https://ui-avatars.com/api/?name=" + user.getName().replace(" ", "+") + "&background=random",
+                Objects.nonNull(user.getPhoto()) ? user.getPhoto() : "https://ui-avatars.com/api/?name=" + user.getName().replace(" ", "+") + "&background=random",
                 token,
                 refreshToken,
                 3600L,

backend/src/main/java/net/beetechgroup/beetask/usecase/auth/refresh/RefreshTokenUseCase.java

@@ -12,6 +12,7 @@ import org.eclipse.microprofile.jwt.JsonWebToken;
 import java.time.LocalDateTime;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
@@ -33,7 +34,7 @@ public class RefreshTokenUseCase {
             JsonWebToken token = jwtParser.parse(input.refreshToken());
             String email = token.getSubject(); // Or token.getName() / token.getClaim(Claims.upn.name())
 
-            if (email == null) {
+            if (Objects.isNull(email)) {
                 throw new RuntimeException("Invalid refresh token: email not found");
             }
 
@@ -77,7 +78,7 @@ public class RefreshTokenUseCase {
             return new LoginOutput(
                     user.getName(),
                     user.getEmail(),
-                    user.getPhoto() != null ? user.getPhoto() : "https://ui-avatars.com/api/?name=" + user.getName().replace(" ", "+") + "&background=random",
+                    Objects.nonNull(user.getPhoto()) ? user.getPhoto() : "https://ui-avatars.com/api/?name=" + user.getName().replace(" ", "+") + "&background=random",
                     newToken,
                     newRefreshToken,
                     3600L,

backend/src/main/java/net/beetechgroup/beetask/usecase/dashboard/DashboardUseCase.java

@@ -7,6 +7,7 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 
 import net.beetechgroup.beetask.entities.task.Task;
 import net.beetechgroup.beetask.entities.task.TaskHistoryItem;
@@ -22,24 +23,20 @@ public class DashboardUseCase {
     }
 
     public DashboardOutput execute(DashboardInput input) {
-        // 1. Fetch tasks worked by user in period
         List<Task> workedTasks = taskRepository.findTasksWorkedByUserInPeriod(
             input.userEmail(), input.startDate(), input.endDate()
         );
 
-        // 2. Fetch tasks finished by user in period
         List<Task> finishedTasks = taskRepository.findTasksFinishedByUserInPeriod(
             input.userEmail(), input.startDate(), input.endDate()
         );
 
-        // 3. Yesterday's tasks
         LocalDateTime startOfYesterday = LocalDateTime.now().minusDays(1).with(LocalTime.MIN);
         LocalDateTime endOfYesterday = LocalDateTime.now().minusDays(1).with(LocalTime.MAX);
         List<Task> yesterdayTasks = taskRepository.findTasksWorkedByUserInPeriod(
             input.userEmail(), startOfYesterday, endOfYesterday
         );
 
-        // Calculate total minutes and project stats
         long totalMinutes = 0;
         Map<Long, DashboardProjectStats> projectStatsMap = new HashMap<>();
 
@@ -51,7 +48,7 @@ public class DashboardUseCase {
 
             totalMinutes += taskMinutesInPeriod;
 
-            if (task.getProject() != null) {
+            if (Objects.nonNull(task.getProject())) {
                 Long projectId = task.getProject().getId();
                 DashboardProjectStats stats = projectStatsMap.getOrDefault(projectId,
                     new DashboardProjectStats(projectId, task.getProject().getName(), 0L));
@@ -73,16 +70,15 @@ public class DashboardUseCase {
     }
 
     private boolean isWithinPeriod(TaskHistoryItem item, LocalDateTime start, LocalDateTime end) {
-        if (item.getStartAt() == null) return false;
+        if (Objects.isNull(item.getStartAt())) return false;
-        // If it started after end or ended before start, it's out
         if (item.getStartAt().isAfter(end)) return false;
-        if (item.getEndAt() != null && item.getEndAt().isBefore(start)) return false;
+        if (Objects.nonNull(item.getEndAt()) && item.getEndAt().isBefore(start)) return false;
         return true;
     }
 
     private long calculateMinutesInRange(TaskHistoryItem item, LocalDateTime start, LocalDateTime end) {
         LocalDateTime effectiveStart = item.getStartAt().isBefore(start) ? start : item.getStartAt();
-        LocalDateTime effectiveEnd = item.getEndAt() == null || item.getEndAt().isAfter(end) ? end : item.getEndAt();
+        LocalDateTime effectiveEnd = Objects.isNull(item.getEndAt()) || item.getEndAt().isAfter(end) ? end : item.getEndAt();
 
         if (effectiveStart.isAfter(effectiveEnd)) return 0;
 

backend/src/main/java/net/beetechgroup/beetask/usecase/task/create/CreateTaskMapper.java

@@ -1,5 +1,6 @@
 package net.beetechgroup.beetask.usecase.task.create;
 
+import java.util.Objects;
 import net.beetechgroup.beetask.entities.task.Task;
 import net.beetechgroup.beetask.entities.task.TaskHistoryItem;
 
@@ -10,7 +11,7 @@ public class CreateTaskMapper {
                 task.getTitle(),
                 task.getDescription(),
                 task.getStatus(),
-                task.getProject() != null ? task.getProject().getName() : null,
+                Objects.nonNull(task.getProject()) ? task.getProject().getName() : null,
                 task.getFinishedAt(),
                 task.getHistory().stream().map(CreateTaskMapper::toTaskHistoryItemOutput).toList());
     }

backend/src/main/java/net/beetechgroup/beetask/usecase/task/create/CreateTaskUseCase.java

@@ -1,5 +1,6 @@
 package net.beetechgroup.beetask.usecase.task.create;
 
+import java.util.Objects;
 import net.beetechgroup.beetask.entities.Project;
 import net.beetechgroup.beetask.entities.task.Task;
 import net.beetechgroup.beetask.usecase.repository.ProjectRepository;
@@ -23,7 +24,7 @@ public class CreateTaskUseCase {
         task.setDescription(input.description());
         task.setStatus(input.status());
 
-        if (input.projectId() != null) {
+        if (Objects.nonNull(input.projectId())) {
             Project project = projectRepository.findProjectById(input.projectId())
                     .orElseThrow(() -> new IllegalArgumentException("Projeto não encontrado com ID: " + input.projectId()));
             task.setProject(project);

backend/src/main/java/net/beetechgroup/beetask/usecase/task/start/StartTaskUseCase.java

@@ -1,12 +1,11 @@
 package net.beetechgroup.beetask.usecase.task.start;
 
-import net.beetechgroup.beetask.entities.User;
+import java.util.Objects;
 import net.beetechgroup.beetask.entities.task.Task;
 import net.beetechgroup.beetask.usecase.repository.TaskRepository;
 import net.beetechgroup.beetask.usecase.repository.UserRepository;
 import net.beetechgroup.beetask.usecase.task.create.CreateTaskMapper;
 import net.beetechgroup.beetask.usecase.task.create.CreateTaskOutput;
-import net.beetechgroup.beetask.usecase.exceptions.UserNotFoundException;
 
 public class StartTaskUseCase {
 
@@ -21,7 +20,7 @@ public class StartTaskUseCase {
     public CreateTaskOutput execute(StartTaskInput input) {
         Task task = taskRepository.findTaskById(input.id());
 
-        if (task.getUser() != null && !task.getUser().getEmail().equals(input.userEmail())) {
+        if (Objects.nonNull(task.getUser()) && !task.getUser().getEmail().equals(input.userEmail())) {
             throw new SecurityException("Você não tem permissão para iniciar esta tarefa.");
         }
 

backend/src/main/java/net/beetechgroup/beetask/usecase/task/update/UpdateTaskUseCase.java

@@ -1,6 +1,7 @@
 package net.beetechgroup.beetask.usecase.task.update;
 
 import java.util.List;
+import java.util.Objects;
 import net.beetechgroup.beetask.entities.Project;
 import net.beetechgroup.beetask.entities.task.Task;
 import net.beetechgroup.beetask.entities.task.TaskHistoryItem;
@@ -24,7 +25,7 @@ public class UpdateTaskUseCase {
     public CreateTaskOutput execute(UpdateTaskInput input) {
         Task task = taskRepository.findTaskById(input.id());
 
-        if (task.getUser() == null) {
+        if (Objects.isNull(task.getUser())) {
             task.setUser(userRepository.findByEmail(input.userEmail())
                 .orElseThrow(() -> new IllegalArgumentException("Usuário não encontrado: " + input.userEmail())));
         }
@@ -33,7 +34,7 @@ public class UpdateTaskUseCase {
         task.setDescription(input.description());
         task.setStatus(input.status());
 
-        if (input.projectId() != null) {
+        if (Objects.nonNull(input.projectId())) {
             Project project = projectRepository.findProjectById(input.projectId())
                     .orElseThrow(() -> new IllegalArgumentException("Projeto não encontrado com ID: " + input.projectId()));
             task.setProject(project);
@@ -41,9 +42,9 @@ public class UpdateTaskUseCase {
             task.setProject(null);
         }
 
-        if (input.history() != null) {
+        if (Objects.nonNull(input.history())) {
             List<TaskHistoryItem> updatedHistory = input.history().stream().map(hInput -> {
-                if (hInput.id() != null) {
+                if (Objects.nonNull(hInput.id())) {
                     return task.getHistory().stream()
                             .filter(existing -> existing.getId().equals(hInput.id()))
                             .findFirst()

backend/src/main/java/net/beetechgroup/beetask/usecase/user/profile/GetUserProfileUseCase.java

@@ -5,6 +5,7 @@ import net.beetechgroup.beetask.entities.organization.UserOrganization;
 import net.beetechgroup.beetask.usecase.repository.UserRepository;
 
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.stream.Collectors;
 
@@ -42,7 +43,7 @@ public class GetUserProfileUseCase {
         return new UserProfileOutput(
                 user.getName(),
                 user.getEmail(),
-                user.getPhoto() != null ? user.getPhoto() : "https://ui-avatars.com/api/?name=" + user.getName().replace(" ", "+") + "&background=random",
+                Objects.nonNull(user.getPhoto()) ? user.getPhoto() : "https://ui-avatars.com/api/?name=" + user.getName().replace(" ", "+") + "&background=random",
                 orgs
         );
     }