Add indicator for processed messages

db/migrate/20250618155041_add_message_ref_to_completion.rb

@@ -0,0 +1,5 @@
+class AddMessageRefToCompletion < ActiveRecord::Migration[8.0]
+  def change
+    add_reference :completions, :message, foreign_key: true
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2025_06_18_122655) do
+ActiveRecord::Schema[8.0].define(version: 2025_06_18_155041) do
   create_table "active_storage_attachments", force: :cascade do |t|
     t.string "name", null: false
     t.string "record_type", null: false
@@ -48,8 +48,10 @@ ActiveRecord::Schema[8.0].define(version: 2025_06_18_122655) do
     t.integer "contest_id", null: false
     t.string "display_time_from_start"
     t.string "display_relative_time"
+    t.integer "message_id"
     t.index ["contest_id"], name: "index_completions_on_contest_id"
     t.index ["contestant_id"], name: "index_completions_on_contestant_id"
+    t.index ["message_id"], name: "index_completions_on_message_id"
     t.index ["puzzle_id"], name: "index_completions_on_puzzle_id"
   end
 
@@ -138,6 +140,7 @@ ActiveRecord::Schema[8.0].define(version: 2025_06_18_122655) do
   add_foreign_key "active_storage_variant_records", "active_storage_blobs", column: "blob_id"
   add_foreign_key "completions", "contestants"
   add_foreign_key "completions", "contests"
+  add_foreign_key "completions", "messages"
   add_foreign_key "completions", "puzzles"
   add_foreign_key "contestants", "contests"
   add_foreign_key "contests", "users"