푸터 외부 링크 스타일 추가 및 SCSS 리팩토링

- footer-link--external 스타일 추가로 외부 링크 시각화
- 불필요한 CSS 줄바꿈 및 공백 제거로 파일 최적화

src/main/resources/static/sass/layout/_footer.scss

@@ -65,6 +65,19 @@
       }
     }
 
+    .footer-link--external {
+      display: inline-flex;
+      align-items: center;
+      gap: 4px;
+
+      .footer-link-external-icon {
+        flex-shrink: 0;
+        width: 14px;
+        height: 14px;
+        color: currentColor;
+      }
+    }
+
     .footer-separator {
       color: #D1D5DB;
       font-size: 16px;

src/main/resources/templates/views/fragment/djbank/footer.html

@@ -11,7 +11,13 @@
           <a th:href="@{/agreements/terms}" class="footer-link">이용약관</a>
           <span class="footer-separator">｜</span>
           <a href="https://www.jejubank.co.kr/hmpg/csct/secuCenr/ptctPlcy/procsPlcy/ctnt.do"
-             target="_blank" rel="noopener noreferrer" class="footer-link">개인정보처리방침</a>
+             target="_blank" rel="noopener noreferrer" class="footer-link footer-link--external">개인정보처리방침<svg class="footer-link-external-icon" width="14" height="14" viewBox="0 0 16 16" fill="none"
+                 xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false">
+              <path d="M6.5 2.5H3.2A1.2 1.2 0 0 0 2 3.7v9.1A1.2 1.2 0 0 0 3.2 14h9.1a1.2 1.2 0 0 0 1.2-1.2V9.5"
+                    stroke="currentColor" stroke-width="1.3" stroke-linecap="round" stroke-linejoin="round"/>
+              <path d="M9.5 2h4.5v4.5M14 2 7.5 8.5" stroke="currentColor" stroke-width="1.3"
+                    stroke-linecap="round" stroke-linejoin="round"/>
+            </svg><span class="sr-only">새 창으로 열림</span></a>
         </div>
         <p class="footer-copyright">Copyright &copy; 2026 JEJU Bank. All Rights Reserved.</p>
       </div>