fix completed_at index

db/migrate/20260627065517_remove_submitters_completed_at_index.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class RemoveSubmittersCompletedAtIndex < ActiveRecord::Migration[8.1]
+  def up
+    remove_index :submitters, %i[completed_at account_id], if_exists: true
+  end
+
+  def down
+    add_index :submitters, %i[completed_at account_id], if_not_exists: true
+  end
+end

db/migrate/20260627083558_add_submitters_completed_at_partial_index.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class AddSubmittersCompletedAtPartialIndex < ActiveRecord::Migration[8.1]
+  def up
+    add_index :submitters, %i[account_id completed_at], where: 'completed_at IS NOT NULL', if_not_exists: true
+  end
+
+  def down
+    remove_index :submitters, %i[account_id completed_at], if_exists: true
+  end
+end