style: add label to auxiliary timer

apps/client/src/features/control/playback/aux-timer/AuxTimer.module.scss

@@ -1,5 +1,12 @@
-.extraRow {
+.label {
+  display: block;
+  margin-top: 2rem;
+  font-size: $inner-section-text-size;
+  color: $label-gray;
+}
+
+.controls {
+  margin-top: 0.25rem;
   display: flex;
   gap: 0.5rem;
-  margin-top: 2rem;
 }

apps/client/src/features/control/playback/aux-timer/AuxTimer.tsx

@@ -29,7 +29,9 @@ export function AuxTimer() {
   };
 
   return (
-    <div className={style.extraRow}>
+    <label className={style.label}>
+      Auxiliary Timer
+      <div className={style.controls}>
         <AuxTimerInput />
         <TapButton onClick={toggleDirection} aspect='tight'>
           {direction === SimpleDirection.CountDown && <IoArrowDown data-testid='aux-timer-direction' />}
@@ -56,6 +58,7 @@ export function AuxTimer() {
           <IoStop data-testid='aux-timer-stop' />
         </TapButton>
       </div>
+    </label>
   );
 }