feat: Add CORS (#10)

* chore: Add rack-cors

* chore: Add initializers/cors.rb

backend/Gemfile

@@ -33,6 +33,8 @@ gem "bootsnap", require: false
 # Use Active Storage variants [https://guides.rubyonrails.org/active_storage_overview.html#transforming-images]
 # gem "image_processing", "~> 1.2"
 
+gem "rack-cors"
+
 group :development, :test do
   # See https://guides.rubyonrails.org/debugging_rails_applications.html#debugging-with-the-debug-gem
   gem "debug", platforms: %i[ mri mingw x64_mingw ]

backend/Gemfile.lock

@@ -117,6 +117,8 @@ GEM
       nio4r (~> 2.0)
     racc (1.7.1)
     rack (2.2.8)
+    rack-cors (2.0.1)
+      rack (>= 2.0.0)
     rack-test (2.1.0)
       rack (>= 1.3)
     rails (7.0.8)
@@ -195,6 +197,7 @@ DEPENDENCIES
   bootsnap
   debug
   puma (~> 5.0)
+  rack-cors
   rails (~> 7.0.8)
   rspec-rails (~> 6.0.3)
   shoulda-matchers (~> 5.0)

backend/config/initializers/cors.rb

@@ -0,0 +1,6 @@
+Rails.application.config.middleware.insert_before 0, Rack::Cors do
+  allow do
+    origins '*'
+    resource '*', headers: :any, methods: [:get, :post, :patch, :put, :delete]
+  end
+end