test(leyline): gate leyline-schema/binary version parity (mache-b8af69)

[jamestexas]

Executable drift guard. mache carries two independent leyline versions:

• the go.mod pin of the Go schema client (…/clients/go/leyline-schema, currently v0.5.6)
• the leylineBinaryVersion const (the daemon binary mache downloads, currently v0.5.7)

Per socket.go's design note the patch may float (a daemon-only LSP fix ships a binary with no wire change), but major.minor must match because that's the wire/schema format the Go client decodes. Today only a comment + a human keeping two pins in lockstep enforce it — the exact setup that produced the stale-cached-0.4.1 skew (mache-0acdf6).

This test parses the leyline-schema require line from go.mod and the leylineBinaryVersion const and fails if their major.minor disagree. 0.5 == 0.5 today (passes); a future minor/major bump to one without the other reddens CI.

Complements the runtime handshake mache-8kif (blocked on LLO shipping a daemon version op — ley-line-open-b9db7f); this is the cheap build-time half that needs no LLO change.

Verification: go test ./internal/leyline/ -run TestLeylineSchemaBinaryVersionParity → PASS; go vet → clean.

[github-actions]

find_smells (advisory)

Scoped to files changed in this PR. Rules below run on the standalone (no-LLO) cross-ref tables; _ast rules (cyclomatic_complexity, long_function, long_file, magic_int_in_comparison) are not exercised here.

No structural smells in changed files. ✓

Rules: the registry is cmd/smell_rules.go (source of truth); see the authoring guide to add one. Advisory only — these are heuristics, not gates.

[Copilot]

Pull request overview

Adds an executable “drift guard” test to ensure the Go leyline-schema client version pinned in go.mod stays compatible with the pinned leyline daemon binary version (leylineBinaryVersion) by enforcing major.minor parity.

Changes:

• Introduce TestLeylineSchemaBinaryVersionParity that reads go.mod, extracts leyline-schema’s vMAJOR.MINOR and compares it to leylineBinaryVersion’s vMAJOR.MINOR.
• Add a small repoRoot helper to locate the module root (by walking up to go.mod) so the test can reliably read the pinned module version.

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