Rename to ref_name so it's aligning with API

app/controllers/projects/artifacts_controller.rb

@@ -60,8 +60,8 @@ class Projects::ArtifactsController < Projects::ApplicationController
   end
 
   def build_from_ref
-    if params[:ref]
-      builds = project.builds_for(params[:build_name], params[:ref])
+    if params[:ref_name]
+      builds = project.builds_for(params[:build_name], params[:ref_name])
 
       builds.success.latest.first
     end

config/routes.rb

@@ -735,8 +735,8 @@ Rails.application.routes.draw do
 
         resources :artifacts, only: [] do
           collection do
-            get :search, path: ':ref/:build_name/*path', format: false,
-                         constraints: { ref: /.+/ } # ref could have /
+            get :search, path: ':ref_name/:build_name/*path', format: false,
+                         constraints: { ref_name: /.+/ } # ref could have /
           end
         end