fix(listener): keep kelp ribbons present at rest

[nicoechaniz]

Outcome\n\nRefines the accepted Inner-anchor kelp renderer so harmonic leaves are a persistent visual bank rather than TTL-gated objects.\n\n- every selected kelp leaf remains visible with gentle ambient motion while playback is active\n- measured activation still launches the causal inner-anchor impulse and glow\n- each main ribbon and whole-ribbon ghost trail is exactly transparent at its inner endpoint and ramps into the body\n- the TTL control remains available only for the older radial comparison modes\n- Stop still decays and clears the whole decorative field\n\n## Evidence\n\n- 39 focused reactive tests green\n- TypeScript green\n- focused ESLint green\n- production build green\n- staging: https://earlybirds-staging.harmonicbeacon.com/\n\n## Isolation\n\nRenderer/UI/docs/tests only. No Web Audio, media graph, HLS, stream, codec, gain, event, LiveKit, authority or payment change.