Variable COMPOSE_VALIDATION_ERROR_CODES`Const`

COMPOSE_VALIDATION_ERROR_CODES: readonly [
"STACK_COMPOSE_PARSE_FAILED",
"STACK_COMPOSE_INVALID",
] = ...

Codes ComposeValidationError carries — branch on these, not on text. A subset of the published STACK_ERROR_CODES catalogue (errors/stack-codes.ts); the satisfies keeps them from drifting out of it.