Function ingest_turn 

pub fn ingest_turn(
    storage: &Path,
    session_id: &str,
    text: &str,
) -> Result<Vec<ContextTag>, String>

Store a chat turn’s CML context into the inforg — only when the message carries explicit tags (deliberate, permissive). The turn’s text + its concept facets become a searchable library entry. Returns the concepts stored (empty if the message had no tags).