Separate Forward auth into it's own models + controller

db/migrate/20251023234744_create_forward_auth_rule_groups.rb

@@ -0,0 +1,10 @@
+class CreateForwardAuthRuleGroups < ActiveRecord::Migration[8.1]
+  def change
+    create_table :forward_auth_rule_groups do |t|
+      t.references :forward_auth_rule, null: false, foreign_key: true
+      t.references :group, null: false, foreign_key: true
+
+      t.timestamps
+    end
+  end
+end