v0.7.18
Per-model failover policy (maximize_cache vs maximize_availability).
- ExactModelPool.failover_mode + ExecutionSnapshot.failover_mode; next_route_candidate honors it.
- maximize_cache: a THROTTLED (429) surfaces to the caller (no cold failover) to preserve prompt-cache affinity; operational deadness (auth/not-found/5xx/transport) and stalled-lane timeouts still fail over in both modes; genuine retryable 408 still redials the warm rung.
- Authored GatewayPoolRecord.failover_mode carried through normalize_gateway_catalog.
- Native crate unchanged (0.3.13).
(#705)