학생 목록 타일 크기 약 1/4로 축소

타일이 너무 크다는 피드백에 따라 crossAxisCount를 늘리고(8/4)
아바타, 폰트, 버튼 크기를 전반적으로 줄여 훨씬 컴팩트한 타일로 변경.

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

lib/ui/teacher_student_management_page.dart

@@ -545,15 +545,12 @@ class _TeacherStudentManagementPageState
     final bool needsReset = student['device'] == '초기화 필요';
 
     return Container(
-      padding: const EdgeInsets.all(14),
+      padding: const EdgeInsets.all(8),
       decoration: BoxDecoration(
         color: Colors.white,
-        borderRadius: BorderRadius.circular(20),
+        borderRadius: BorderRadius.circular(14),
         boxShadow: [
-          BoxShadow(
-            color: Colors.black.withValues(alpha: 0.04),
-            blurRadius: 12,
-          ),
+          BoxShadow(color: Colors.black.withValues(alpha: 0.04), blurRadius: 8),
         ],
       ),
       child: Column(
@@ -561,43 +558,47 @@ class _TeacherStudentManagementPageState
         crossAxisAlignment: CrossAxisAlignment.center,
         children: [
           CircleAvatar(
-            radius: 24,
+            radius: 14,
             backgroundColor: needsReset ? Colors.red[50] : Colors.blue[50],
             child: Icon(
               needsReset ? Icons.lock_reset : Icons.person,
+              size: 14,
               color: needsReset ? Colors.red : Colors.blue,
             ),
           ),
-          const SizedBox(height: 10),
+          const SizedBox(height: 4),
           Text(
             '$studentName ($studentId)',
             textAlign: TextAlign.center,
             maxLines: 1,
             overflow: TextOverflow.ellipsis,
-            style: const TextStyle(fontWeight: FontWeight.bold, fontSize: 13),
+            style: const TextStyle(fontWeight: FontWeight.bold, fontSize: 10),
           ),
-          const SizedBox(height: 4),
+          const SizedBox(height: 1),
           Text(
             needsReset ? '초기화 대기중' : '정상 등록',
             textAlign: TextAlign.center,
             style: TextStyle(
-              fontSize: 11,
+              fontSize: 8,
               color: needsReset ? Colors.red : Colors.grey,
               fontWeight: needsReset ? FontWeight.bold : FontWeight.normal,
             ),
           ),
-          const SizedBox(height: 10),
+          const SizedBox(height: 4),
           Wrap(
             alignment: WrapAlignment.center,
-            spacing: 2,
-            runSpacing: 2,
+            spacing: 0,
+            runSpacing: 0,
             children: [
               Builder(
                 builder: (chipContext) => ActionChip(
                   visualDensity: VisualDensity.compact,
+                  materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
+                  padding: EdgeInsets.zero,
+                  labelPadding: const EdgeInsets.symmetric(horizontal: 4),
                   label: Text(
                     grade != null ? '$grade학년' : '미배정',
-                    style: const TextStyle(fontSize: 11),
+                    style: const TextStyle(fontSize: 8),
                   ),
                   onPressed: () => _showGradeMenu(
                     chipContext,
@@ -608,23 +609,25 @@ class _TeacherStudentManagementPageState
                 ),
               ),
               IconButton(
-                visualDensity: VisualDensity.compact,
                 icon: const Icon(
                   Icons.lock_reset,
                   color: Colors.purple,
-                  size: 20,
+                  size: 14,
                 ),
                 tooltip: '기기 리셋',
+                padding: EdgeInsets.zero,
+                constraints: const BoxConstraints(minWidth: 22, minHeight: 22),
                 onPressed: () => _confirmResetDevice(studentId, studentName),
               ),
               IconButton(
-                visualDensity: VisualDensity.compact,
                 icon: const Icon(
                   Icons.delete_forever_rounded,
                   color: Colors.redAccent,
-                  size: 20,
+                  size: 14,
                 ),
                 tooltip: '계정 영구 삭제',
+                padding: EdgeInsets.zero,
+                constraints: const BoxConstraints(minWidth: 22, minHeight: 22),
                 onPressed: () => _confirmDeleteStudent(studentId, studentName),
               ),
             ],
@@ -759,10 +762,10 @@ class _TeacherStudentManagementPageState
                                   physics: const NeverScrollableScrollPhysics(),
                                   gridDelegate:
                                       SliverGridDelegateWithFixedCrossAxisCount(
-                                        crossAxisCount: isWide ? 4 : 2,
-                                        crossAxisSpacing: 16,
-                                        mainAxisSpacing: 16,
-                                        childAspectRatio: isWide ? 1.5 : 0.75,
+                                        crossAxisCount: isWide ? 8 : 4,
+                                        crossAxisSpacing: 10,
+                                        mainAxisSpacing: 10,
+                                        childAspectRatio: isWide ? 1.4 : 0.9,
                                       ),
                                   itemCount: _controller.students.length,
                                   itemBuilder: (context, index) =>