Allow closing accounts

Closes #37

db/migrate/20260420181729_add_closed_at_to_user.rb

@@ -0,0 +1,5 @@
+class AddClosedAtToUser < ActiveRecord::Migration[7.2]
+  def change
+    add_column :users, :closed_at, :datetime
+  end
+end

db/migrate/20260420210736_add_opened_at_to_vote.rb

@@ -0,0 +1,5 @@
+class AddOpenedAtToVote < ActiveRecord::Migration[7.2]
+  def change
+    add_column :votes, :opened_at, :datetime
+  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[7.2].define(version: 2026_03_23_215246) do
+ActiveRecord::Schema[7.2].define(version: 2026_04_20_210736) do
   create_table "candidates", force: :cascade do |t|
     t.integer "vote_id"
     t.string "name"
@@ -46,6 +46,7 @@ ActiveRecord::Schema[7.2].define(version: 2026_03_23_215246) do
     t.datetime "updated_at", null: false
     t.string "reset"
     t.boolean "admin"
+    t.datetime "closed_at"
   end
 
   create_table "votes", force: :cascade do |t|
@@ -57,6 +58,7 @@ ActiveRecord::Schema[7.2].define(version: 2026_03_23_215246) do
     t.datetime "updated_at", null: false
     t.string "state"
     t.integer "reminders"
+    t.datetime "opened_at"
   end
 
   add_foreign_key "ratings", "votes"