feat(#21): contas bancárias e patrimônio consolidado

CRUD de contas (corrente/poupança/investimento/cartão) com saldo calculado
automaticamente. account_id nullable em transactions. Widget patrimônio no
dashboard. Tela /contas. Seletor de conta nas transações manuais.

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

apps/api/internal/service/account_test.go

@@ -0,0 +1,68 @@
+package service_test
+
+import (
+	"context"
+	"testing"
+
+	"financeiro-carvalho/internal/model"
+	"financeiro-carvalho/internal/service"
+)
+
+type mockAccountRepo struct {
+	items []model.Account
+}
+
+func (m *mockAccountRepo) List(_ context.Context) ([]model.Account, error) { return m.items, nil }
+func (m *mockAccountRepo) GetByID(_ context.Context, id int) (*model.Account, error) {
+	for _, a := range m.items {
+		if a.ID == id {
+			cp := a
+			return &cp, nil
+		}
+	}
+	return nil, nil
+}
+func (m *mockAccountRepo) Create(_ context.Context, in model.AccountInput) (*model.Account, error) {
+	a := model.Account{ID: len(m.items) + 1, Name: in.Name, Type: in.Type, InitialBalance: in.InitialBalance, Balance: in.InitialBalance}
+	m.items = append(m.items, a)
+	return &a, nil
+}
+func (m *mockAccountRepo) Update(_ context.Context, id int, in model.AccountInput) (*model.Account, error) {
+	for i, a := range m.items {
+		if a.ID == id {
+			m.items[i].Name = in.Name
+			cp := m.items[i]
+			return &cp, nil
+		}
+	}
+	return nil, nil
+}
+func (m *mockAccountRepo) Delete(_ context.Context, _ int) error       { return nil }
+func (m *mockAccountRepo) TotalPatrimony(_ context.Context) (float64, error) { return 0, nil }
+
+func TestCreateAccount_EmptyName(t *testing.T) {
+	svc := service.NewAccountService(&mockAccountRepo{})
+	_, err := svc.Create(context.Background(), model.AccountInput{Name: "", Type: "checking", InitialBalance: 0})
+	if err != service.ErrAccountEmptyName {
+		t.Fatalf("expected ErrAccountEmptyName, got %v", err)
+	}
+}
+
+func TestCreateAccount_InvalidType(t *testing.T) {
+	svc := service.NewAccountService(&mockAccountRepo{})
+	_, err := svc.Create(context.Background(), model.AccountInput{Name: "Nubank", Type: "bitcoin"})
+	if err != service.ErrAccountInvalidType {
+		t.Fatalf("expected ErrAccountInvalidType, got %v", err)
+	}
+}
+
+func TestCreateAccount_OK(t *testing.T) {
+	svc := service.NewAccountService(&mockAccountRepo{})
+	a, err := svc.Create(context.Background(), model.AccountInput{Name: "Nubank", Type: "checking", InitialBalance: 1000})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if a.Name != "Nubank" || a.Balance != 1000 {
+		t.Errorf("unexpected account: %+v", a)
+	}
+}