feat: add transient suppressor to audio pipeline

Implements a per-sample transient suppressor in the noise gate AudioWorklet
that instantly cuts gain when a sudden loud peak (desk hit, mic bump) exceeds
the slow background RMS by a configurable threshold, then releases over a
short window. Exposes enable, sensitivity, and release controls in the audio
settings tab.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/settings/settings.ts

@@ -145,6 +145,21 @@ export const noiseGateHold = new Setting<number>("noise-gate-hold", 200);
 // Time in ms for the gate to fully close after hold expires
 export const noiseGateRelease = new Setting<number>("noise-gate-release", 150);
 
+export const transientSuppressorEnabled = new Setting<boolean>(
+  "transient-suppressor-enabled",
+  false,
+);
+// How many dB above the background RMS a peak must be to trigger suppression
+export const transientThreshold = new Setting<number>(
+  "transient-suppressor-threshold",
+  15,
+);
+// Time in ms for suppression to fade after transient ends
+export const transientRelease = new Setting<number>(
+  "transient-suppressor-release",
+  80,
+);
+
 export enum MatrixRTCMode {
   Legacy = "legacy",
   Compatibility = "compatibility",