Land the two real pre-passes as canonical *derived annotations* (pure
functions of the materialized Score + profile, recomputed on
materialization, never serialized into canonical Score bytes), exposed via
`derive_annotations`:
- Spelling: a Temperley-style line-of-fifths centre-of-gravity preference
rule (key-free, deterministic), preserving authored CMN letters and only
inferring spelling for chromatic/integer input. `resolve_spelling`
layers authored overrides above the inferred default (the RespellPitch
precedence rule). `spell` now takes `&Pitch` and delegates to
`simplest_spelling`.
- Decomposition: metric greedy-aligned splitting on a 1/4096 integer grid
(barline + dyadic-boundary ties), with exact sounding->notated tuplet
conversion before gridding. Components reconstruct the event duration
(invariant 15).
- A per-event-kind eligibility `TaxonomyReport` so "ineligible" is always
explicit and counted, never silently absent.
Test infrastructure (Agent F): a 29-fixture representative corpus +
taxonomy harness (corpus.rs), the H spelling/decomposition merge gate
(prepass_harness.rs), a discrete `tests/prepass.rs` CI target, conformance
stage [7b], a dedicated CI job, and the Pass-12 batch tracker.
Review hardening folded in (nine findings):
- Guard `decompose_metric` against a zero-length measure (was a
divide-by-zero panic; now reported ungriddable).
- Resolve spelling-override priority via `Reverse` instead of negation
(was an i32::MIN overflow).
- Verify spelling *register* (octave), not just pitch class, in the gate.
- Close the decomposition under-emission gap: the unusual-outcome
taxonomy buckets are an exact per-fixture whitelist (classify_corpus
step 5b).
- Generalize `accidental_ids` to a glyph stack so authored extreme
alterations (triple-sharp+) reconstruct exactly instead of being clamped.
- Per-fixture spread checks in the non-vacuity tripwire and broad-bucket
coverage, so no single rich fixture can carry a signal (partial-stub
resistance); added a `mixed_rhythm` fixture for margin.
- Pin the integer-grid note-value math to the canonical rational helpers
via an exhaustive test; cross-reference comments.
- Replace the O(n^2) tuplet innermost-resolution scan with an id index.
fmt + clippy -D warnings clean; 199 tests pass; conformance suite green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011giSRaHCFCGm1Z2SWv6JHt