refactor(shell): KakaoFloatButton 컴포넌트 추출 — PublicShell 인라인 → 별도 컴포넌트

D 트랙 2/4. P1 Task 3 review I-1 후속:
- PublicShell의 인라인 카카오 버튼 JSX + style 블록 → KakaoFloatButton.tsx
- KAKAO_OPENCHAT_URL은 lib/contact 에서 import
- SVG에 aria-hidden 추가 (parent aria-label 우선)

향후 admin shell 또는 다른 surface에서 재사용 가능.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/components/KakaoFloatButton.tsx

@@ -0,0 +1,62 @@
+import { KAKAO_OPENCHAT_URL } from '@/lib/contact';
+
+/**
+ * 카카오 1:1 상담 플로팅 버튼.
+ * PublicShell footer 다음에 마운트되어 모든 공개 페이지에 노출.
+ */
+export default function KakaoFloatButton() {
+  return (
+    <>
+      <a
+        href={KAKAO_OPENCHAT_URL}
+        target="_blank"
+        rel="noopener noreferrer"
+        className="kakao-float-btn"
+        aria-label="카카오 오픈채팅 상담"
+        title="카카오 오픈채팅으로 1:1 상담"
+      >
+        <svg width="28" height="28" viewBox="0 0 24 24" fill="currentColor" aria-hidden>
+          <path d="M12 3C6.477 3 2 6.589 2 11c0 2.713 1.574 5.117 4 6.663V21l3.5-2.1A11.5 11.5 0 0 0 12 19c5.523 0 10-3.589 10-8s-4.477-8-10-8z"/>
+        </svg>
+        <span className="kakao-float-label">1:1 상담</span>
+      </a>
+
+      <style>{`
+        .kakao-float-btn {
+          position: fixed;
+          bottom: 28px;
+          right: 28px;
+          z-index: 50;
+          display: flex;
+          align-items: center;
+          gap: 8px;
+          background: #FEE500;
+          color: #3A1D1D;
+          padding: 12px 18px;
+          border-radius: 100px;
+          font-weight: 700;
+          font-size: 14px;
+          text-decoration: none;
+          box-shadow: 0 4px 20px rgba(254,229,0,0.4), 0 2px 8px rgba(0,0,0,0.15);
+          transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
+          white-space: nowrap;
+        }
+        .kakao-float-btn:hover {
+          transform: translateY(-3px) scale(1.04);
+          box-shadow: 0 8px 28px rgba(254,229,0,0.5), 0 4px 12px rgba(0,0,0,0.15);
+        }
+        .kakao-float-btn:active {
+          transform: translateY(-1px) scale(0.98);
+        }
+        @media (max-width: 640px) {
+          .kakao-float-btn {
+            bottom: 20px;
+            right: 16px;
+            padding: 10px 14px;
+            font-size: 13px;
+          }
+        }
+      `}</style>
+    </>
+  );
+}

app/components/PublicShell.tsx

@@ -1,5 +1,6 @@
 import TopNav from './TopNav';
 import Link from 'next/link';
+import KakaoFloatButton from './KakaoFloatButton';
 
 export default function PublicShell({ children }: { children: React.ReactNode }) {
   return (
@@ -116,57 +117,7 @@ export default function PublicShell({ children }: { children: React.ReactNode })
         </footer>
       </main>
 
-      {/* 카카오 오픈채팅 플로팅 버튼 */}
+      <KakaoFloatButton />
-      <a
-        href="https://open.kakao.com/o/s9stoNvb"
-        target="_blank"
-        rel="noopener noreferrer"
-        className="kakao-float-btn"
-        aria-label="카카오 오픈채팅 상담"
-        title="카카오 오픈채팅으로 1:1 상담"
-      >
-        <svg width="28" height="28" viewBox="0 0 24 24" fill="currentColor">
-          <path d="M12 3C6.477 3 2 6.589 2 11c0 2.713 1.574 5.117 4 6.663V21l3.5-2.1A11.5 11.5 0 0 0 12 19c5.523 0 10-3.589 10-8s-4.477-8-10-8z"/>
-        </svg>
-        <span className="kakao-float-label">1:1 상담</span>
-      </a>
-
-      <style>{`
-        .kakao-float-btn {
-          position: fixed;
-          bottom: 28px;
-          right: 28px;
-          z-index: 50;
-          display: flex;
-          align-items: center;
-          gap: 8px;
-          background: #FEE500;
-          color: #3A1D1D;
-          padding: 12px 18px;
-          border-radius: 100px;
-          font-weight: 700;
-          font-size: 14px;
-          text-decoration: none;
-          box-shadow: 0 4px 20px rgba(254,229,0,0.4), 0 2px 8px rgba(0,0,0,0.15);
-          transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
-          white-space: nowrap;
-        }
-        .kakao-float-btn:hover {
-          transform: translateY(-3px) scale(1.04);
-          box-shadow: 0 8px 28px rgba(254,229,0,0.5), 0 4px 12px rgba(0,0,0,0.15);
-        }
-        .kakao-float-btn:active {
-          transform: translateY(-1px) scale(0.98);
-        }
-        @media (max-width: 640px) {
-          .kakao-float-btn {
-            bottom: 20px;
-            right: 16px;
-            padding: 10px 14px;
-            font-size: 13px;
-          }
-        }
-      `}</style>
     </>
   );
 }