-- Migration 8: Support chat sessions for both notebooks and sources
-- This migration allows chat_session to refer to either a notebook or a source

DEFINE TABLE OVERWRITE refers_to
TYPE RELATION 
FROM chat_session TO notebook|source;

-- Add model_override field to chat_session for per-session model selection
DEFINE FIELD model_override ON chat_session TYPE option<string>;

DEFINE FIELD command ON source TYPE option<record<command>>;