[#1946] Check if a dossier’s retention period has expired

app/models/dossier.rb

@@ -183,6 +183,16 @@ class Dossier < ApplicationRecord
     brouillon? || en_construction?
   end
 
+  def retention_end_date
+    if instruction_commencee?
+      en_instruction_at + procedure.duree_conservation_dossiers_dans_ds.months
+    end
+  end
+
+  def retention_expired?
+    instruction_commencee? && retention_end_date <= DateTime.now
+  end
+
   def text_summary
     if brouillon?
       parts = [