선생님 호출 화면 이모티콘을 검정 아이콘으로 통일

위치 이모티콘(🏢🍴🧪 등)을 Material 아이콘으로, 랭킹 메달 이모티콘을
백품타 랭킹 화면과 같은 금/은/동 색 emoji_events 아이콘으로 교체.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

lib/ui/teacher_location_screen.dart

@@ -112,13 +112,25 @@ class _TeacherLocationScreenState extends State<TeacherLocationScreen> {
                               ),
                             ),
                             const SizedBox(height: 6),
-                            Text(
-                              '${kLocationIcons[_controller.currentLocation] ?? '📍'} ${_controller.currentLocation}',
-                              style: const TextStyle(
-                                fontWeight: FontWeight.bold,
-                                fontSize: 20,
-                                color: Colors.white,
-                              ),
+                            Row(
+                              mainAxisAlignment: MainAxisAlignment.center,
+                              children: [
+                                Icon(
+                                  kLocationIcons[_controller.currentLocation] ??
+                                      Icons.location_on_rounded,
+                                  color: Colors.white,
+                                  size: 20,
+                                ),
+                                const SizedBox(width: 8),
+                                Text(
+                                  _controller.currentLocation,
+                                  style: const TextStyle(
+                                    fontWeight: FontWeight.bold,
+                                    fontSize: 20,
+                                    color: Colors.white,
+                                  ),
+                                ),
+                              ],
                             ),
                           ],
                         ),
@@ -177,9 +189,13 @@ class _TeacherLocationScreenState extends State<TeacherLocationScreen> {
                                             : AppPalette.linen,
                                         shape: BoxShape.circle,
                                       ),
-                                      child: Text(
-                                        kLocationIcons[loc] ?? '📍',
-                                        style: const TextStyle(fontSize: 16),
+                                      child: Icon(
+                                        kLocationIcons[loc] ??
+                                            Icons.location_on_rounded,
+                                        size: 16,
+                                        color: isSelected
+                                            ? Colors.white
+                                            : AppPalette.ink,
                                       ),
                                     ),
                                     const SizedBox(height: 6),