grain-llm-models vs llm-registry-core vs llm-registry-db

Standardized LLM model registry for grain-agent. Embeds a vendored snapshot of model metadata (context window, capabilities, pricing, thinking profile); the `fetch` feature pulls live data from models.dev.

Core domain types and models for the LLM Registry - A secure, production-ready registry for Large Language Models

Database layer for the LLM Registry - PostgreSQL integration with migrations and repository patterns