Function store_error 

pub fn store_error(
    ctx: Context,
    node_type: &str,
    op: &str,
    store: &str,
    msg: String,
) -> PluginExecutionError

A store outage. Never conflated with a miss: see the spec’s §7. Prepares a 503 – the dependency is unavailable, not the caller’s fault – so a policy that wires error -> client cannot fail open with a 200.

Not feature-gated: the #[cfg(not(feature = "redis-store"))] execute bodies in all four plugins call this too, to report “built without the redis-store feature” with the same shape.