refac: register only open while no verified acc exists, enforced by a use case rather than handler & sends verification email whose link uses the conf pub URL whose code expires after 2h

test/use_case_baseline_test.go

@@ -440,7 +440,7 @@ func TestDeleteImageRequiresExistence(t *testing.T) {
 
 func TestCreateUserAssignsVerificationCode(t *testing.T) {
 	repo := newMockUserRepo()
-	uc := useCases.NewCreateUserUseCase(repo, &stubHasher{})
+	uc := useCases.NewCreateUserUseCase(repo, &stubHasher{}, newMockMailRepo(), "https://cms.example.com")
 
 	before := time.Now()
 	result, err := uc.CreateUser(useCases.CreateUserCommand{
@@ -487,7 +487,7 @@ func TestCreateUserAssignsVerificationCode(t *testing.T) {
 func TestCreateUserPropagatesRepositoryFailure(t *testing.T) {
 	repo := newMockUserRepo()
 	repo.fail.failNext("Create")
-	uc := useCases.NewCreateUserUseCase(repo, &stubHasher{})
+	uc := useCases.NewCreateUserUseCase(repo, &stubHasher{}, newMockMailRepo(), "https://cms.example.com")
 
 	_, err := uc.CreateUser(useCases.CreateUserCommand{
 		Username: "alice",