Vocabulary: runtime names, conformance facts and CI target sets from the catalog #112

Part of ComlineProject/core#219, proposal ComlineProject/docs#162 (rollout stage 3). Blocked on ComlineProject/core#220.

• Generated constants for the runtime's names: contract/names.rs (FORMAT_*, FRAMING_*, HANDSHAKE_*).
• Conformance: Fact::name() in conformance/src/profile.rs, the fact domains in specs/profile.cue, and the feature ids in features.json.
• CI: the fuzz target matrix and the Observatory expect: list in fuzz.yml, and the bench target lists, generated from vocabulary sets. Today packed_canonical is written in Cargo.toml, twice in fuzz.yml, in the README and in seed_corpus.rs.
• A CI check that the generated files are current, the way comline.h is checked.

Update (2026-11-09): the catalog is leaning towards a spec repository (ComlineProject/core#220). The conformance specs (specs/, features.json) and the vectors would move there from runtime/conformance. The Rust engine, the reference and vectors_are_current stay here, reading the spec at a pinned revision.