[diegosouzapw]

Summary

• deletes public/audio/ui-notify.mp3, whose origin and license could not be established
• preserves optional audible feedback for both Model Lockout toggles with a locally synthesized 100 ms Web Audio chime (880 Hz sine + deterministic gain envelope)
• creates the AudioContext only from the toggle gesture, resumes suspended contexts, fails open when Web Audio is unavailable or rejected, and closes the context when the card unmounts
• adds no replacement asset, package, dependency, or copied third-party code

Evidence and status

Area	Status	Evidence
Binary provenance	RESOLVED BY REMOVAL	Deleted the unresolved 172,619-byte MP3 (SHA-256 4a716f2a47d4fa230840e14ecc96965ba6be05c62c1cafa9e6f7c540e458a42f); Git history remains recoverable from base 0915890 if an audit needs the original bytes.
Legacy runtime reference	PASS	Physical repository search returns no /audio/ui-notify.mp3 reference and the regression guard verifies both the file and component reference remain absent.
Toggle behavior	PASS	Both Model Lockout switches create and schedule generated oscillator feedback; legacy Audio asset playback is not called.
Browser fallback	PASS	Missing Web Audio leaves both toggles functional; suspended contexts resume before scheduling; resume rejection is swallowed without blocking the setting change.
Resource lifecycle	PASS	One context is reused per mounted card, oscillator/gain nodes disconnect on completion, and the context closes on unmount.
Scope	PASS	Only the unresolved asset, its sole consumer, and a focused UI regression test changed.

TDD evidence

Phase	Result
RED (provenance + generated feedback)	npm exec -- vitest run --config vitest.config.ts tests/unit/ui/model-lockout-notify-chime.test.tsx → 2 failed / 2 while the MP3 still existed and the generated-feedback contract was unmet.
RED (behavior tracer)	After removing the legacy reference, the focused suite produced 1 failed / 2: expected two oscillators from the two toggle gestures, received zero.
RED (resource tracer)	The focused suite produced 1 failed / 3 because the initial module-global context was not owned/released by the mounted card.
GREEN	npm run test:vitest:ui -- tests/unit/ui/model-lockout-notify-chime.test.tsx → 6 passed / 6.

Additional validation

Command	Result
focused ESLint with repository suppressions, no cache	PASS
npm run typecheck:core	PASS
git diff --check	PASS
physical exact-path search + asset existence check	PASS (no runtime reference; asset absent)

This PR is intentionally draft/open. It does not merge, tag, publish, release, or deploy anything.

Independent review follow-up

• Independent correctness and Standards/Security reviews found no blocking defect.
• Focused Vitest evidence is now 7/7 PASS after commit 87ecda603b.
• The regression suite now proves one reused AudioContext, two synthesized oscillators, the 880 Hz / 100 ms envelope, oscillator-to-gain-to-destination wiring, per-note node cleanup, and the webkitAudioContext fallback.
• Browser autoplay/user-activation policy remains configured by code inspection, not live-browser verified; no browser-compatibility claim is made here.