The reversible half of the remaining tuning work: make tuning resolvable --
(position, tuning system, reference) -> frequency, walking the five resolution
scopes -- entirely in memory, no Codec, canonical bytes byte-identical. The
schema-major-3 wire bump is a separate later tranche, so the resolution logic is
exercised and proven before anything freezes, the same slice discipline tranche
1 used.
Scope is nine of twenty systems: the six tet-* (EqualTemperament) and the three
ji-static-5limit-* (PerPositionRatios computed from the lattice block, not a
pasted table). The ten historical temperaments are tranche 2b -- their own
verify-heavy pass, because that is where S6's two impossible-but-cited
temperaments hid and the code re-derivation deserves the same closure-invariant
scrutiny. ji-adaptive-5limit and the compatibility-mapping registry are deferred
fail-closed, matching the established honest-gap pattern (user ratified both).
Names the struct_codec! trap concretely: adding an in-memory `overrides` field
to ScoreTuningContext breaks the macro (its dec constructs a literal of exactly
the named fields), so the contract requires a hand-written Codec that encodes
the three wire fields and defaults overrides -- with a round-trip test proving
overrides never reaches the wire.
Citations verified line-by-line before dispatch; two were wrong on first draft
(tuning-resolution-order and -compatibility cited by the numbers of unrelated
requirements, one left hedged) and are fixed -- P13-S9's own discipline applied
to the contract that cites P13-S9.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
