docs(spec): 009 note-detection capability domain (draft stub, refs #727)

[byrongamatos]

🗂️ Migrated PR. Originally opened by @mogul on 2026-06-18 (was #516). Review history not preserved.

Reconstructed from slopsmith/slopsmith#728 — original PR by @byrongamatos. Commits replayed with original authorship onto the current main.

Refs #727.

Adds specs/009-note-detection-domain/ (spec.md + plan.md) — a draft stub scheduling the next capability-domain slice after audio-input (006) and audio-monitoring (007).

What it specifies

A per-binding, chart-decoupled, multi-consumer control plane over the existing detection DSP:

• Exposes two primitives — a monophonic pitch estimate and a polyphonic note-set verification verdict — each scored against a requester-supplied tuning context (so a contained-playback consumer scores against the player's real instrument, not whatever song the host highway has loaded).
• Consolidates the two fragmented detection surfaces (slopsmithMinigames.scoring.createContinuous mono-YIN + window.noteDetect) behind one contract → one DSP source of truth, so improvements (bass persistence floor, distortion, future models) land once and reach every consumer.
• Realizes Spec 004's deliberate "no single global detector assumption" via per-binding context.
• Does not implement DSP and does not own consumer judgment (host owns DSP; consumers own gems/tiers/accuracy).

Why a stub

Per the spec-kit flow, this PR is spec.md + plan.md only; data-model / contracts / tasks are generated when the slice is scheduled, passing the Spec 003 migration gate. It depends on 006 and 007 (007 currently paused at #667), so it isn't startable yet — this fixes the scope and names the requesters now.

Relation to the "work now" bridge

The interim, forward-compatible step is already in flight on the plugin: notedetect setVerifyTarget(notes, ctx) (slopsmith/slopsmith-plugin-notedetect#62), consumed by a SlopScale adapter (fork PR). Its per-call tuning context maps 1:1 onto this domain's per-binding context — the bridge is re-pointed, not discarded, when the domain lands.

No code/runtime changes; docs only.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Documentation
  • Added detailed specification and implementation plan for the Note-Detection capability domain, documenting the architecture for monophonic pitch estimation and polyphonic note verification features with support for per-binding tuning context.