Function is_spawn_gate_refusal 

pub(crate) fn is_spawn_gate_refusal(error: &str) -> bool

Whether a delivery error is the identity/credential spawn gate refusing to start the target (run_agent_turn’s “identity spawn gate: …”). That is recoverable — the receiver signs in — so the message is held, not dropped (SPEC_JEKT_DELIVERY_STATES_AND_MAILBOX_2026_10_01.md Phase 0 item 4, G4).