Implement projected time

db/migrate/20251114092752_add_projected_time_to_completion.rb

@@ -0,0 +1,5 @@
+class AddProjectedTimeToCompletion < ActiveRecord::Migration[8.0]
+  def change
+    add_column :completions, :projected_time, :integer
+  end
+end

db/migrate/20251114093213_add_completion_to_offline.rb

@@ -0,0 +1,5 @@
+class AddCompletionToOffline < ActiveRecord::Migration[8.0]
+  def change
+    add_reference :offlines, :completion, foreign_key: true
+  end
+end