pub const CANCELED_PREFIX: &str = "canceled: ";Expand description
Prefix on the error field of an ActionResult that distinguishes
“the user pulled the plug” from “earlier abort cascaded.” The
ActionStatus itself is Skipped in both cases (introducing a
new variant ripples through every IR consumer + FFI binding); the
prefix lets callers like the A2A bridge tell the cases apart
without string-matching a magic literal.