Add allow_browser :modern and clean up assets initializer

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: dadachi

app/controllers/non_api_application_controller.rb

@@ -1,3 +1,4 @@
 class NonApiApplicationController < ActionController::Base
+  allow_browser versions: :modern
   protect_from_forgery with: :exception
 end

config/initializers/assets.rb

@@ -5,8 +5,3 @@
 
 # Add additional assets to the asset load path.
 # Rails.application.config.assets.paths << Emoji.images_path
-
-# Precompile additional assets.
-# application.js, application.css, and all non-JS/CSS in the app/assets
-# folder are already added.
-# Rails.application.config.assets.precompile += %w( admin.js admin.css )