docs: sync AGENTS.md files against post-#141 codebase

[slittycode]

$(cat <<'EOF'

Summary

• Audited all documentation against the current codebase structure and found two per-app AGENTS.md files drifted after recent feature commits
• apps/backend/AGENTS.md: missing 5 entries from the pluggable separation backend (feat(backend): pluggable stem-separation backend (Demucs ↔ MSST/BS-RoFormer) #141), which updated CLAUDE.md but not the backend overlay
• apps/ui/AGENTS.md: missing patchSmith.ts from the File Map, which landed in WS4: patchSmith — downloadable Vital (.vital) presets with cited parameters #130

Changes

apps/backend/AGENTS.md — 5 new entries:

• separation_backend.py (selectable Demucs ↔ MSST stem-separation backend)
• separation_ab.py (research-only A/B harness, paired with above)
• tests/test_separation_backend.py (unit coverage for the above)
• msst_separate_runner.py in the Operator and Research Scripts section
• ab_separation_backends.py in the Operator and Research Scripts section

apps/ui/AGENTS.md — 1 new entry:

• patchSmith.ts (Phase 3 Vital preset generation service)

What was checked

Audited top-level files, apps/backend/*.py (46 files), apps/ui/src/services/*.ts, apps/ui/src/utils/, apps/ui/src/hooks/, apps/ui/src/types/, apps/ui/src/data/, scripts/, docs/, docs/adr/, docs/history/, audits/, incorporations/ — all against the claims in CLAUDE.md, apps/backend/AGENTS.md, apps/ui/AGENTS.md, GOAL.md, and NEEDS.md. CLAUDE.md was already fully up to date after #141.

Test plan

• No code changes; documentation only
• All existing tests remain unchanged

https://claude.ai/code/session_011v17uVcfV8rM9EQpRn72Ra
EOF
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Generated by Claude Code

[slittycode]

Verdict: APPROVE

Summary

Docs-only sync of two per-app AGENTS.md files against code that landed in #130 and #141. Six new entries total across apps/backend/AGENTS.md (separation backend, A/B harness, test module, two script entries) and apps/ui/AGENTS.md (patchSmith service). All referenced files exist, descriptions are accurate against the codebase, and the "research-only / off-the-product-path" claims hold (separation_ab.py is only imported by scripts/ab_separation_backends.py; patchSmith.ts is correctly described as surfaced through PatchSmithPanel.tsx).

Findings

None.

Test results

N/A — no code changes.

Phase boundary check

Clean.

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Generated by Claude Code

[slittycode]

Verdict: COMMENT

Summary

Docs-only sync of two AGENTS.md files against post-#141 state. All 6 new entries are for real files that exist. Five of the six descriptions are accurate. One is not.

Findings

Should fix — apps/ui/AGENTS.md, patchSmith.ts entry:

builds a .vital preset JSON from Phase 1 measurements and Phase 2 recommendations

This is wrong. buildPatch(phase1: Phase1Result, ...) is the sole export surface and it only accepts Phase 1. There is no import of any Phase 2 type and no reference to Phase2Result, AbletonRecommendation, or anything from the interpretation layer. The module docstring explicitly says "derived from Phase 1 synthesis measurements." Saying "Phase 2 recommendations" mischaracterizes where the numbers come from — which matters because chain-of-custody is a core invariant of this project and AGENTS.md is read by agents making changes.

Correct description:

src/services/patchSmith.ts: Phase 3 Vital preset generation — builds a .vital preset JSON from Phase 1 measurements alone, with every parameter citing the exact Phase 1 field(s) that justify it. Surfaced in components/PatchSmithPanel.tsx.

Test results

4/4 CI checks green (Backend, Frontend, Loudness WASM, Chromatic). No test impact — docs only.

Phase boundary check

Clean. No code changes.

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Generated by Claude Code