fix(voice): retune the remote playback leveller and measure it in float (#1784)

fluxer_app/src/features/voice/engine/v2/VoiceEngineV2AppRemoteSpeakingAdapter.test.ts

@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {describe, expect, it, vi} from 'vitest';
+import {computeTimeDomainRms} from './VoiceEngineV2AppRemoteSpeakingAdapter';
+
+vi.mock('@app/features/voice/state/ParticipantVolume', () => ({default: {}}));
+vi.mock('@app/features/voice/state/VoiceSettings', () => ({default: {getVadThreshold: () => 50}}));
+
+describe('computeTimeDomainRms', () => {
+	it('returns the amplitude of an alternating full-scale-relative signal', () => {
+		const samples = new Float32Array(512);
+		for (let i = 0; i < samples.length; i++) {
+			samples[i] = i % 2 === 0 ? 0.09 : -0.09;
+		}
+		expect(computeTimeDomainRms(samples)).toBe(Math.fround(0.09));
+	});
+
+	it('returns zero for digital silence', () => {
+		expect(computeTimeDomainRms(new Float32Array(512))).toBe(0);
+	});
+
+	it('returns zero for an empty buffer', () => {
+		expect(computeTimeDomainRms(new Float32Array(0))).toBe(0);
+	});
+
+	it('spreads a single full-scale sample across the window', () => {
+		const samples = new Float32Array(512);
+		samples[17] = 1;
+		expect(computeTimeDomainRms(samples)).toBeCloseTo(1 / Math.sqrt(512), 12);
+	});
+
+	it('resolves levels far below one 8-bit quantisation step', () => {
+		expect(computeTimeDomainRms(Float32Array.of(0.0005, -0.0005))).toBe(Math.fround(0.0005));
+	});
+});