Commit iniziale di eminuxCRM: CRM Rails con pipeline, campagne email e Docker.

Include autenticazione, progetti isolati, mail marketing HTML con SMTP, test A/B e editor WYSIWYG.

Co-authored-by: Cursor <cursoragent@cursor.com>

db/migrate/20260817173000_add_ab_test_to_mailings.rb

@@ -0,0 +1,16 @@
+class AddAbTestToMailings < ActiveRecord::Migration[8.1]
+  def change
+    change_table :mailings do |t|
+      t.boolean :ab_test, default: false, null: false
+      t.string :ab_assignment, default: "from_record", null: false
+      t.string :subject_b
+      t.text :body_html_b
+      t.bigint :mail_template_b_id
+    end
+    add_index :mailings, :ab_test
+    add_foreign_key :mailings, :mail_templates, column: :mail_template_b_id
+
+    add_column :mailing_recipients, :ab_variant, :string
+    add_index :mailing_recipients, :ab_variant
+  end
+end