新增：声明感知消息

app/models/issue.rb

@@ -65,6 +65,7 @@ class Issue < ApplicationRecord
   has_many :journals, :as => :journalized, :dependent => :destroy
   has_many :journal_details, through: :journals
   has_many :claims, :dependent => :destroy
+  has_many :claim_users, through: :claims, source: :user
   has_many :issue_tags_relates, dependent: :destroy
   has_many :issue_tags, through: :issue_tags_relates
   has_many :issue_times, dependent: :destroy