feat: Allow configuring OpenRouter API base via openrouter_api_base s…

[graysonchen]

What this does

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]

Why?

[graysonchen]

Hey @crmne Yep, for integrate Cloudflare AI Gateway

With this, we can quickly pinpoint issues and access logs.

[crmne]

I see. Since it's OpenAI compatible, instead of adding another configuration option to the library, can't you do the following and use the OpenAI provider instead?

RubyLLM.configure do |config|
  config.openai_api_base = '<cloudflare api gateway url>'
  config.openai_use_system_role = true
end