This pull request upgrades the application from Rails 6.1 to Rails 7.1, updates related dependencies, and makes several configuration adjustments to ensure compatibility with the new Rails version. The most important changes are grouped below.

Rails and Dependency Upgrades:

• Upgraded Rails from 6.1.3 to 7.1.0 in the Gemfile, updated puma to ~> 6.0, added webrick, and set Ruby version to 3.3.5. Also adjusted the platform for tzinfo-data to match Windows and JRuby. [1] [2]
• Updated migration parent class in db/migrate/20250820144718_create_puppies.rb to inherit from ActiveRecord::Migration[7.1] instead of 6.1.

Configuration Adjustments for Rails 7.1:

• Changed config.load_defaults from 6.1 to 7.1 and set config.active_support.cache_format_version = 7.1 in config/application.rb.
• Updated test environment to use config.action_dispatch.show_exceptions = :none for Rails 7.1 compatibility.

RSpec and Test Suite Updates:

• Required rails_helper instead of spec_helper in .rspec and reordered options.
• Updated rspec-rails to ~> 6.0.0 in the Gemfile and made related changes in spec/rails_helper.rb for compatibility, including using require_relative for environment loading, improved error handling for pending migrations, and updated documentation links. [1] [2] [3] [4]
• Removed unnecessary require 'rspec/json_expectations' and updated documentation links in spec/spec_helper.rb. [1] [2] [3]

Other Notable Changes:

• Removed commented-out or obsolete configuration lines in various files, such as asset pipeline settings in config/environments/development.rb and forgery protection in app/controllers/application_controller.rb. [1] [2]