CREATE TABLE IF NOT EXISTS agent_knowledge_base (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    session UUID NOT NULL,
    title TEXT NOT NULL,
    source_type TEXT NOT NULL,
    source_url TEXT,
    content TEXT,
    embedding_ref TEXT,
    created_by UUID NOT NULL,
    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
    deleted_at TIMESTAMPTZ
);