fix(task): restore task metadata contract and type fields in task types api

backend/plugins/domain/user/plugin.go

@@ -140,16 +140,90 @@ func (p *Plugin) Apply(ctx *core.Context) error {
 		}
 	}
 
-	const defaultUserTaskRetry = 3
+	const (
+		defaultUserTaskRetry = 3
+		paramTypeString      = "string"
+		paramNameEmail       = "email"
+	)
 
 	// 4. Register background tasks
 	ctx.Task().Register("user:send_email_code", func(_ context.Context, _ []byte) error {
 		return nil
-	}, extpoints.WithTaskRetry(defaultUserTaskRetry))
+	},
+		extpoints.WithTaskType("send_email_code"),
+		extpoints.WithTaskName("发送邮箱验证码"),
+		extpoints.WithTaskDescription("异步发送用户注册与验证邮箱验证码"),
+		extpoints.WithTaskCategory("user"),
+		extpoints.WithTaskRetry(defaultUserTaskRetry),
+		extpoints.WithTaskQueue("default"),
+		extpoints.WithTaskRetryable(true),
+		extpoints.WithTaskParams(
+			contracts.TaskParamDTO{
+				Name:        paramNameEmail,
+				Label:       "目标邮箱",
+				Type:        paramTypeString,
+				Required:    true,
+				Placeholder: "user@example.com",
+				Description: "接收验证码的目标邮箱",
+			},
+			contracts.TaskParamDTO{
+				Name:        "code",
+				Label:       "验证码",
+				Type:        paramTypeString,
+				Required:    true,
+				Placeholder: "123456",
+				Description: "6 位数字验证码",
+			},
+		),
+	)
+
+	ctx.Task().Register("mail:send", func(_ context.Context, _ []byte) error {
+		return nil
+	},
+		extpoints.WithTaskType("send_email"),
+		extpoints.WithTaskName("发送邮件"),
+		extpoints.WithTaskDescription("异步发送系统邮件"),
+		extpoints.WithTaskCategory("mail"),
+		extpoints.WithTaskRetry(defaultUserTaskRetry),
+		extpoints.WithTaskQueue("default"),
+		extpoints.WithTaskRetryable(true),
+		extpoints.WithTaskParams(
+			contracts.TaskParamDTO{
+				Name:        "to",
+				Label:       "接收邮箱 (To)",
+				Type:        paramTypeString,
+				Required:    true,
+				Placeholder: "receiver@example.com",
+				Description: "接收邮件的目标邮箱地址",
+			},
+			contracts.TaskParamDTO{
+				Name:        "subject",
+				Label:       "邮件主题 (Subject)",
+				Type:        paramTypeString,
+				Required:    true,
+				Placeholder: "请输入邮件主题",
+				Description: "发送邮件的主题标题",
+			},
+			contracts.TaskParamDTO{
+				Name:        "body",
+				Label:       "邮件内容 (Body)",
+				Type:        "text",
+				Required:    true,
+				Placeholder: "请输入邮件内容（支持 HTML格式）",
+				Description: "发送邮件的内容主体",
+			},
+		),
+	)
 
 	ctx.Task().Register("user:cleanup_inactive", func(_ context.Context, _ []byte) error {
 		return nil
-	})
+	},
+		extpoints.WithTaskType("cleanup_inactive_users"),
+		extpoints.WithTaskName("清理未激活用户"),
+		extpoints.WithTaskDescription("清理长期未激活的注册用户与临时凭据"),
+		extpoints.WithTaskCategory("user"),
+		extpoints.WithTaskQueue("default"),
+	)
 
 	// 5. Register Settings Schemas
 	ctx.Settings().Register(extpoints.SettingSchema{