Maps the AssetOverflow audio-compiler proposal onto the existing
sensorium ProjectionHead boundary (ADR-0013) and the Delta-CRDT
sharded substrate (ADR-0180).
Core mapping decision: the audio chunk boundary IS the CRDT delta
boundary. In-chunk rotor composition (compile_events) is the explicit
serialization barrier ADR-0180 §1.5.2 requires for non-commutative
versor_apply; the resulting AudioCompilationUnit is the order-invariant
delta written at the only semilattice-eligible layer (vault/store).
The compiler's checksum chain supplies the content-addressed merge key
(canonical, ir, projection sha256) that ADR-0180 §1.5.3 demands, making
idempotence structural and the sequential==concurrent trace-hash proof
checkable.
Adds:
- docs/decisions/ADR-0181-audio-compiler-delta-crdt.md (decision + mapping)
- docs/plans/audio-compiler-spec.md (typed AudioIR, operator table,
manifest, numeric determinism, delta interface)
- docs/plans/audio-compiler-eval-plan.md (corpus, gates, A-1..A-6 CRDT
proof obligations, teacher-migration policy)
Docs only; no runtime/core mutation. PR-2..PR-6 substrate work sequenced
in the ADR, with PR-5 gated on ADR-0180 §1.5.4 (T-1..T-4) green on main.
