Rails Upgrade Analyzer

Analyze the current Rails application and provide a comprehensive upgrade assessment with selective file merging.

Step 1: Verify Rails Application

Check that we're in a Rails application by looking for these files:

• Gemfile (must exist and contain 'rails')
• config/application.rb (Rails application config)
• config/environment.rb (Rails environment)

If any of these are missing or don't indicate a Rails app, stop and inform the user this doesn't appear to be a Rails application.

Step 2: Get Current Rails Version

Extract the current Rails version from:

1. First, check Gemfile.lock for the exact installed version (look for rails (x.y.z))
2. If not found, check Gemfile for the version constraint