[Feature]: RubyLLM as provider

[tpaulshippy]

Problem statement

Providers other than anthropic or openai are not available.

Proposed solution

Add support for using RubyLLM as a provider, thereby unlocking a large ecosystem of providers.

Alternatives considered

Adding Ollama, Bedrock, Gemini, xAI, OpenRouter, etc. directly as providers.

Impact and verification

Run with keys from one of these other providers (or ollama with no keys).