refactor(i18n): 사용자 문구 참조를 중앙화

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

@@ -1,6 +1,7 @@
 'use client';
 
 import { useEffect, useRef, useState, type ReactNode } from 'react';
+import { copy } from '@/shared/i18n';
 import { cn } from '@/shared/lib/cn';
 import { useReducedMotion } from '@/shared/lib/useReducedMotion';
 
@@ -100,7 +101,7 @@ export const SpaceSideSheet = ({
       {dismissible ? (
         <button
           type="button"
-          aria-label="시트 닫기"
+          aria-label={copy.modal.closeAriaLabel}
           onClick={onClose}
           className={cn(
             'fixed inset-0 z-40 bg-slate-950/14 backdrop-blur-[1px] transition-opacity',
@@ -147,7 +148,7 @@ export const SpaceSideSheet = ({
                 <button
                   type="button"
                   onClick={onClose}
-                  aria-label="닫기"
+                  aria-label={copy.modal.closeButton}
                   className="inline-flex h-7 w-7 items-center justify-center rounded-full border border-white/14 bg-white/6 text-[12px] text-white/72 transition-colors hover:bg-white/12 hover:text-white"
                 >
                   ✕