Fixing failing of prepare_for_active_storage method when attachment is of type ActiveStorage::Attached::One

[sisodiaa]

What this does

Say there is a model user with one attached profile_document, then following method call would fail resulting in NoMethodError.

chat_record.ask("What's in this document?", with: user.profile_document)
# undefined method 'blobs' for an instance of ActiveStorage::Attached::One (NoMethodError)

To fix this error we need to modify switch statement in prepare_for_active_storage method i.e. for ActiveStorage::Attached::One we should return attachment.blob instead of attachment.blobs.

Type of change

• Bug fix
• New feature
• Breaking change
• Documentation
• Performance improvement

Scope check

• I read the Contributing Guide
• This aligns with RubyLLM's focus on LLM communication
• This isn't application-specific logic that belongs in user code
• This benefits most users, not just my specific use case

Quality check

• I ran overcommit --install and all hooks pass
• I tested my changes thoroughly
• I updated documentation if needed
• I didn't modify auto-generated files manually (models.json, aliases.json)

API changes

• Breaking change
• New public methods/classes
• Changed method signatures
• No API changes

[codecov]

Codecov Report

❌ Patch coverage is 0% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 84.61%. Comparing base (34e8d75) to head (3b6574d).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/ruby_llm/active_record/chat_methods.rb	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #380      +/-   ##
==========================================
- Coverage   84.65%   84.61%   -0.05%     
==========================================
  Files          35       35              
  Lines        1825     1826       +1     
  Branches      492      493       +1     
==========================================
  Hits         1545     1545              
- Misses        280      281       +1     

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[crmne]

Could you add one test?