refactor(quick-controls): 사운드 역할 분리와 패널 레이아웃·오버레이 개선

src/widgets/space-sheet-shell/ui/SpaceSideSheet.tsx

@@ -14,6 +14,7 @@ interface SpaceSideSheetProps {
   widthClassName?: string;
   dismissible?: boolean;
   headerAction?: ReactNode;
+  overlayClassName?: string;
 }
 
 export const SpaceSideSheet = ({
@@ -26,6 +27,7 @@ export const SpaceSideSheet = ({
   widthClassName,
   dismissible = true,
   headerAction,
+  overlayClassName,
 }: SpaceSideSheetProps) => {
   const reducedMotion = useReducedMotion();
   const transitionMs = reducedMotion ? 0 : 260;
@@ -97,6 +99,7 @@ export const SpaceSideSheet = ({
             'fixed inset-0 z-40 bg-slate-950/14 backdrop-blur-[1px] transition-opacity',
             reducedMotion ? 'duration-0' : 'duration-[240ms]',
             visible ? 'opacity-100' : 'pointer-events-none opacity-0',
+            overlayClassName,
           )}
         />
       ) : (
@@ -106,6 +109,7 @@ export const SpaceSideSheet = ({
             'fixed inset-0 z-40 bg-slate-950/8 backdrop-blur-[1px] transition-opacity',
             reducedMotion ? 'duration-0' : 'duration-[240ms]',
             visible ? 'opacity-100' : 'opacity-0',
+            overlayClassName,
           )}
         />
       )}