Add OIDC fixes, add prefered_username, add application-user claims

db/migrate/20251123052026_create_application_user_claims.rb

@@ -0,0 +1,13 @@
+class CreateApplicationUserClaims < ActiveRecord::Migration[8.1]
+  def change
+    create_table :application_user_claims do |t|
+      t.references :application, null: false, foreign_key: { on_delete: :cascade }
+      t.references :user, null: false, foreign_key: { on_delete: :cascade }
+      t.json :custom_claims, default: {}, null: false
+
+      t.timestamps
+    end
+
+    add_index :application_user_claims, [:application_id, :user_id], unique: true, name: 'index_app_user_claims_unique'
+  end
+end