feat(pop-work-detail): 모든 그룹 작업완료 버튼 항상 표시 + 타이머 완료 버튼 추가

- GroupCompleteButton: !isGroupCompleted 조건 제거 → 모든 그룹에서 항상 표시
  - 이미 완료된 그룹에서는 "작업완료됨" 완료 표시 렌더링
  - isGroupCompleted prop 추가
- GroupTimerHeader: isGroupStarted 상태(진행 중/일시정지)에 완료 버튼 추가
  - GlossyButton green variant, onTimerAction("complete") 호출

frontend/lib/registry/pop-components/pop-work-detail/PopWorkDetailComponent.tsx

@@ -1253,12 +1253,13 @@ export function PopWorkDetailComponent({
                       ))}
 
                       {/* 각 그룹 하단: 작업완료 버튼 */}
-                      {!isProcessCompleted && selectedGroup && !isGroupCompleted && (
+                      {!isProcessCompleted && selectedGroup && (
                         <div className="mt-3 mb-2">
                           <GroupCompleteButton
                             group={selectedGroup}
                             currentItems={currentItems}
                             isGroupStarted={isGroupStarted}
+                            isGroupCompleted={isGroupCompleted}
                             onComplete={async () => {
                               await handleGroupTimerAction("complete");
                               // 완료 후 다음 그룹으로 자동 이동
@@ -2274,6 +2275,11 @@ function GroupTimerHeader({
                   <Play className="h-5 w-5" />재개
                 </GlossyButton>
               )}
+              {isGroupStarted && (
+                <GlossyButton variant="green" onClick={() => onTimerAction("complete")} style={{ minHeight: 48, minWidth: 120, fontSize: 16 }}>
+                  <Check className="h-5 w-5" />완료
+                </GlossyButton>
+              )}
             </div>
           )}
         </div>
@@ -2427,12 +2433,14 @@ function GroupCompleteButton({
   group,
   currentItems,
   isGroupStarted,
+  isGroupCompleted,
   onComplete,
   onNavigateNext,
 }: {
   group: WorkGroup;
   currentItems: WorkResultRow[];
   isGroupStarted: boolean;
+  isGroupCompleted: boolean;
   onComplete: () => void;
   onNavigateNext: () => void;
 }) {
@@ -2442,6 +2450,19 @@ function GroupCompleteButton({
   const allDone = currentItems.every((r) => r.status === "completed");
   const isDisabled = !isGroupStarted || (!allRequiredDone);
 
+  // 이미 완료된 그룹: 완료 표시만
+  if (isGroupCompleted) {
+    return (
+      <div
+        className="flex items-center justify-center gap-2 rounded-2xl border-2 border-green-400 bg-green-50"
+        style={{ width: '100%', minHeight: 64, fontSize: 20, color: '#16a34a', borderRadius: 16 }}
+      >
+        <Check className="h-6 w-6" />
+        작업완료됨
+      </div>
+    );
+  }
+
   if (confirmOpen) {
     return (
       <div className="flex items-center gap-3">