chore: add Sentry errors monitoring

Gemfile

@@ -85,3 +85,9 @@ group :development do
   # Speed up commands on slow machines / big apps [https://github.com/rails/spring]
   # gem "spring"
 end
+
+group :production do
+  # Monitoring and error reporting
+  gem "sentry-rails"
+  gem "sentry-ruby"
+end

Gemfile.lock

@@ -328,6 +328,12 @@ GEM
       rubocop-rspec (~> 3, >= 3.0.1)
     ruby-progressbar (1.13.0)
     securerandom (0.3.1)
+    sentry-rails (5.21.0)
+      railties (>= 5.0)
+      sentry-ruby (~> 5.21.0)
+    sentry-ruby (5.21.0)
+      bigdecimal
+      concurrent-ruby (~> 1.0, >= 1.0.2)
     shellany (0.0.1)
     sprockets (4.2.1)
       concurrent-ruby (~> 1.0)
@@ -395,6 +401,8 @@ DEPENDENCIES
   rubocop-rails
   rubocop-rspec
   rubocop-rspec_rails
+  sentry-rails
+  sentry-ruby
   sprockets-rails
   stimulus-rails
   turbo-rails

config/initializers/sentry.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+if defined?(Sentry)
+  Sentry.init do |config|
+    config.dsn = ENV.fetch("SENTRY_DSN")
+    config.breadcrumbs_logger = %i[active_support_logger http_logger]
+
+    # Set traces_sample_rate to 1.0 to capture 100%
+    # of transactions for performance monitoring.
+    # We recommend adjusting this value in production.
+    config.traces_sample_rate = 0.5
+  end
+end