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/SettingsModal.tsx

@@ -29,6 +29,9 @@ import {
   noiseGateAttack as noiseGateAttackSetting,
   noiseGateHold as noiseGateHoldSetting,
   noiseGateRelease as noiseGateReleaseSetting,
+  transientSuppressorEnabled as transientSuppressorEnabledSetting,
+  transientThreshold as transientThresholdSetting,
+  transientRelease as transientReleaseSetting,
 } from "./settings";
 import { PreferencesSettingsTab } from "./PreferencesSettingsTab";
 import { Slider } from "../Slider";
@@ -126,6 +129,13 @@ export const SettingsModal: FC<Props> = ({
 
   const [showAdvancedGate, setShowAdvancedGate] = useState(false);
 
+  // Transient suppressor settings
+  const [transientEnabled, setTransientEnabled] = useSetting(transientSuppressorEnabledSetting);
+  const [transientThreshold, setTransientThreshold] = useSetting(transientThresholdSetting);
+  const [transientThresholdRaw, setTransientThresholdRaw] = useState(transientThreshold);
+  const [transientRelease, setTransientRelease] = useSetting(transientReleaseSetting);
+  const [transientReleaseRaw, setTransientReleaseRaw] = useState(transientRelease);
+
   const resetGateDefaults = useCallback((): void => {
     const a = noiseGateAttackSetting.defaultValue;
     const h = noiseGateHoldSetting.defaultValue;
@@ -293,6 +303,62 @@ export const SettingsModal: FC<Props> = ({
           </>
         )}
         </div>
+        <div className={styles.noiseGateSection}>
+          <Heading
+            type="body"
+            weight="semibold"
+            size="sm"
+            as="h4"
+            className={styles.noiseGateHeading}
+          >
+            Transient Suppressor
+          </Heading>
+          <Separator className={styles.noiseGateSeparator} />
+          <FieldRow>
+            <InputField
+              id="transientEnabled"
+              type="checkbox"
+              label="Enable transient suppressor"
+              description="Cut sudden loud impacts like desk hits or mic bumps."
+              checked={transientEnabled}
+              onChange={(e: ChangeEvent<HTMLInputElement>): void =>
+                setTransientEnabled(e.target.checked)
+              }
+            />
+          </FieldRow>
+          {transientEnabled && (
+            <>
+              <div className={`${styles.volumeSlider} ${styles.thresholdSlider}`}>
+                <span className={styles.sliderLabel}>Sensitivity: {transientThresholdRaw} dB above background</span>
+                <p>Lower values catch more impacts; higher values only catch the loudest ones.</p>
+                <Slider
+                  label="Transient threshold"
+                  value={transientThresholdRaw}
+                  onValueChange={setTransientThresholdRaw}
+                  onValueCommit={setTransientThreshold}
+                  min={8}
+                  max={30}
+                  step={1}
+                  tooltip={false}
+                />
+              </div>
+              <div className={styles.volumeSlider}>
+                <span className={styles.sliderLabel}>Release: {transientReleaseRaw} ms</span>
+                <p>How quickly audio returns after suppression.</p>
+                <Slider
+                  label="Transient release"
+                  value={transientReleaseRaw}
+                  onValueChange={setTransientReleaseRaw}
+                  onValueCommit={setTransientRelease}
+                  min={20}
+                  max={200}
+                  step={10}
+                  tooltip={false}
+                />
+              </div>
+            </>
+          )}
+        </div>
       </>
     ),
   };