ConstBumping this constant is a SPEC change: the cross-bridge contract with the eventual Rust port (issue #697 deliverable #1) requires both sides to agree on the encoded shape. Any structural rename, variant addition, or field-order change increments the version and triggers a coordinated update on both the TS and Rust evaluators.
The version is intentionally a string rather than a number so that
pre-1.0 deliberation ('0.1.0', '0.2.0-rc') and post-1.0 SemVer
('1.0.0') share the same field shape.
Wire-IR version string for the formula AST + result shapes exported from this module.