Function shape_consistent 

pub fn shape_consistent(declared: &[i64], computed: &ShapeValue) -> bool

KISS-CONTRACT-6.4-0011: the Interface declared output shape is consistent iff it equals the op’s shape rule computed over the operand shapes. A surfaced Gap (symbolic/data-dependent output) is never a hard inconsistency — a consumer cannot assert a mismatch it cannot compute. The shape-side companion to the §6.4-0006 value oracle.