Feat: Add support to Action Text enabled content

[chagel]

What this does

Improved the extract_content method to correctly process Action Text. When message model uses has_rich_text :content, message.content becomes ActionText:RichText, returning HTML tags unintentionally. Adjustments ensure only the desired content is extracted.

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

Related issues

[crmne]

Can you add some tests?

[chagel]

Can you add some tests?

@crmne Added basic tests and modified dummy app for instance double.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.68%. Comparing base (32611af) to head (c5f8706).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #365      +/-   ##
==========================================
+ Coverage   84.65%   84.68%   +0.02%     
==========================================
  Files          35       35              
  Lines        1825     1828       +3     
  Branches      492      494       +2     
==========================================
+ Hits         1545     1548       +3     
  Misses        280      280              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.