feat: add rack-mini-profiler for performance monitoring

- Include 'rack-mini-profiler' gem in Gemfile
- Update Gemfile.lock with the new dependency
- Create initializer for rack-mini-profiler in development

This addition allows for performance monitoring within the
application during development, which can help identify
and address performance issues more effectively.

Gemfile

@@ -80,7 +80,8 @@ group :development do
   # Use console on exceptions pages [https://github.com/rails/web-console]
   gem "web-console"
 
-  gem 'bullet', '~> 8.0'
+  gem "bullet", "~> 8.0"
+  gem "rack-mini-profiler", "~> 3.3"
 end
 
 group :production do

Gemfile.lock

@@ -319,6 +319,8 @@ GEM
     raabro (1.4.0)
     racc (1.8.1)
     rack (3.1.9)
+    rack-mini-profiler (3.3.1)
+      rack (>= 1.2.0)
     rack-session (2.1.0)
       base64 (>= 0.1.0)
       rack (>= 3.0.0)
@@ -537,6 +539,7 @@ DEPENDENCIES
   pg (~> 1.5)
   propshaft
   puma (>= 5.0)
+  rack-mini-profiler (~> 3.3)
   rails (~> 8.0.1)
   rubocop-rails-omakase
   ruby-openai (~> 7.3)

config/initializers/rack_mini_profiler.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+if Rails.env.development?
+  require "rack-mini-profiler"
+
+  # The initializer was required late, so initialize it manually.
+  # Rack::MiniProfilerRails.initialize!(Rails.application)
+end