Fix the inaccessible problem of signup page (#6730)

#### What type of PR is this?

/kind bug
/area core
/milestone 2.20.x

#### What this PR does / why we need it:

This PR adds confirmPassword field into SignUpData for validation. So the signup page can be rendered correctly.

See https://github.com/halo-dev/halo/issues/6718 for more.

#### Which issue(s) this PR fixes:

Fixes https://github.com/halo-dev/halo/issues/6718

#### Special notes for your reviewer:

#### Does this PR introduce a user-facing change?

```release-note
None
```

application/src/main/java/run/halo/app/core/user/service/SignUpData.java

@@ -1,7 +1,16 @@
 package run.halo.app.core.user.service;
 
+import jakarta.validation.Constraint;
+import jakarta.validation.ConstraintValidator;
+import jakarta.validation.ConstraintValidatorContext;
+import jakarta.validation.Payload;
 import jakarta.validation.constraints.Email;
 import jakarta.validation.constraints.NotBlank;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.util.Objects;
 import java.util.Optional;
 import lombok.Data;
 import org.springframework.util.MultiValueMap;
@@ -14,6 +23,7 @@ import org.springframework.util.StringUtils;
  * @since 2.20.0
  */
 @Data
+@SignUpData.SignUpDataConstraint
 public class SignUpData {
 
     @NotBlank
@@ -30,6 +40,9 @@ public class SignUpData {
     @NotBlank
     private String password;
 
+    @NotBlank
+    private String confirmPassword;
+
     public static SignUpData of(MultiValueMap<String, String> formData) {
         var form = new SignUpData();
         Optional.ofNullable(formData.getFirst("username"))
@@ -52,6 +65,41 @@ public class SignUpData {
             .filter(StringUtils::hasText)
             .ifPresent(form::setEmailCode);
 
+        Optional.ofNullable(formData.getFirst("confirmPassword"))
+            .filter(StringUtils::hasText)
+            .ifPresent(form::setConfirmPassword);
+
         return form;
     }
+
+    @Target({ElementType.TYPE})
+    @Retention(RetentionPolicy.RUNTIME)
+    @Constraint(validatedBy = {SignUpDataConstraintValidator.class})
+    public @interface SignUpDataConstraint {
+
+        String message() default "";
+
+        Class<?>[] groups() default { };
+
+        Class<? extends Payload>[] payload() default { };
+
+    }
+
+    private static class SignUpDataConstraintValidator
+        implements ConstraintValidator<SignUpDataConstraint, SignUpData> {
+
+        @Override
+        public boolean isValid(SignUpData signUpData, ConstraintValidatorContext context) {
+            var isValid = Objects.equals(signUpData.getPassword(), signUpData.getConfirmPassword());
+            if (!isValid) {
+                context.disableDefaultConstraintViolation();
+                context.buildConstraintViolationWithTemplate(
+                        "{signup.error.confirm-password-not-match}"
+                    )
+                    .addPropertyNode("confirmPassword")
+                    .addConstraintViolation();
+            }
+            return isValid;
+        }
+    }
 }

application/src/main/java/run/halo/app/security/preauth/PreAuthSignUpEndpoint.java

@@ -103,8 +103,7 @@ class PreAuthSignUpEndpoint {
                                         "emailCode",
                                         signUpData.getEmailCode(),
                                         true,
-                                        // TODO Refine i18n
+                                        new String[] {"signup.error.email-code.invalid"},
-                                        new String[] {"signup.error.email-captcha.invalid"},
                                         null,
                                         "Invalid Email Code"));
                                 }

application/src/main/resources/config/i18n/messages.properties

@@ -82,4 +82,6 @@ problemDetail.attachment.upload.fileSizeExceeded=Make sure the file size is less
 problemDetail.attachment.upload.fileTypeNotSupported=Unsupported upload of {0} type files.
 problemDetail.comment.waitingForApproval=Comment is awaiting approval.
 
-title.visibility.identification.private=(Private)
+title.visibility.identification.private=(Private)
+signup.error.confirm-password-not-match=The confirmation password does not match the password.
+signup.error.email-code.invalid=Invalid email code.

application/src/main/resources/config/i18n/messages_zh.properties

@@ -54,4 +54,6 @@ problemDetail.attachment.upload.fileSizeExceeded=最大支持上传 {0} 大小
 problemDetail.attachment.upload.fileTypeNotSupported=不支持上传 {0} 类型的文件。
 problemDetail.comment.waitingForApproval=评论审核中。
 
-title.visibility.identification.private=（私有）
+title.visibility.identification.private=（私有）
+signup.error.confirm-password-not-match=确认密码与密码不匹配。
+signup.error.email-code.invalid=邮箱验证码无效。

application/src/main/resources/templates/signup.html

@@ -141,13 +141,13 @@
                     <div class="form-item">
                         <label for="confirmPassword" th:text="#{form.confirmPassword.label}"></label>
                         <th:block
-                            th:replace="~{gateway_modules/input_fragments :: password(id = 'confirmPassword', name = null, required = 'true', minlength = 6, enableToggle = true)}"
+                            th:replace="~{gateway_modules/input_fragments :: password(id = 'confirmPassword', name = 'confirmPassword', required = 'true', minlength = 6, enableToggle = true)}"
                         ></th:block>
-                        <!-- <p -->
+                         <p
-                        <!--     class="alert alert-error" -->
+                             class="alert alert-error"
-                        <!--     th:if="${#fields.hasErrors('confirmPassword')}" -->
+                             th:if="${#fields.hasErrors('confirmPassword')}"
-                        <!--     th:errors="*{confirmPassword}" -->
+                             th:errors="*{confirmPassword}"
-                        <!-- ></p> -->
+                         ></p>
                     </div>
 
                     <div class="form-item">