학생 목록 타일 글자 확대 + 계정 추가/엑셀 칸을 학생 타일 크기로 통일

학생 타일의 이름/상태/학년칩 폰트와 아이콘 크기를 키워 가독성을
높이고, 계정 추가/엑셀 등록 정사각형 칸의 크기를 학생 목록 타일과
동일한 크기(tileSize)로 통일했다.

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

lib/ui/teacher_student_management_page.dart

@@ -558,47 +558,46 @@ class _TeacherStudentManagementPageState
         crossAxisAlignment: CrossAxisAlignment.center,
         children: [
           CircleAvatar(
-            radius: 14,
+            radius: 20,
             backgroundColor: needsReset ? Colors.red[50] : Colors.blue[50],
             child: Icon(
               needsReset ? Icons.lock_reset : Icons.person,
-              size: 14,
+              size: 20,
               color: needsReset ? Colors.red : Colors.blue,
             ),
           ),
-          const SizedBox(height: 4),
+          const SizedBox(height: 6),
           Text(
             '$studentName ($studentId)',
             textAlign: TextAlign.center,
             maxLines: 1,
             overflow: TextOverflow.ellipsis,
-            style: const TextStyle(fontWeight: FontWeight.bold, fontSize: 10),
+            style: const TextStyle(fontWeight: FontWeight.bold, fontSize: 15),
           ),
-          const SizedBox(height: 1),
+          const SizedBox(height: 2),
           Text(
             needsReset ? '초기화 대기중' : '정상 등록',
             textAlign: TextAlign.center,
             style: TextStyle(
-              fontSize: 8,
+              fontSize: 12,
               color: needsReset ? Colors.red : Colors.grey,
               fontWeight: needsReset ? FontWeight.bold : FontWeight.normal,
             ),
           ),
-          const SizedBox(height: 4),
+          const SizedBox(height: 6),
           Wrap(
             alignment: WrapAlignment.center,
-            spacing: 0,
-            runSpacing: 0,
+            spacing: 2,
+            runSpacing: 2,
             children: [
               Builder(
                 builder: (chipContext) => ActionChip(
                   visualDensity: VisualDensity.compact,
                   materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
-                  padding: EdgeInsets.zero,
-                  labelPadding: const EdgeInsets.symmetric(horizontal: 4),
+                  labelPadding: const EdgeInsets.symmetric(horizontal: 6),
                   label: Text(
                     grade != null ? '$grade학년' : '미배정',
-                    style: const TextStyle(fontSize: 8),
+                    style: const TextStyle(fontSize: 12),
                   ),
                   onPressed: () => _showGradeMenu(
                     chipContext,
@@ -612,22 +611,22 @@ class _TeacherStudentManagementPageState
                 icon: const Icon(
                   Icons.lock_reset,
                   color: Colors.purple,
-                  size: 14,
+                  size: 20,
                 ),
                 tooltip: '기기 리셋',
                 padding: EdgeInsets.zero,
-                constraints: const BoxConstraints(minWidth: 22, minHeight: 22),
+                constraints: const BoxConstraints(minWidth: 30, minHeight: 30),
                 onPressed: () => _confirmResetDevice(studentId, studentName),
               ),
               IconButton(
                 icon: const Icon(
                   Icons.delete_forever_rounded,
                   color: Colors.redAccent,
-                  size: 14,
+                  size: 20,
                 ),
                 tooltip: '계정 영구 삭제',
                 padding: EdgeInsets.zero,
-                constraints: const BoxConstraints(minWidth: 22, minHeight: 22),
+                constraints: const BoxConstraints(minWidth: 30, minHeight: 30),
                 onPressed: () => _confirmDeleteStudent(studentId, studentName),
               ),
             ],
@@ -657,12 +656,14 @@ class _TeacherStudentManagementPageState
             padding: const EdgeInsets.all(24.0),
             child: LayoutBuilder(
               builder: (context, constraints) {
-                // 🖥️ 웹(넓은 화면)은 계정 추가/엑셀 등록을 작은 정사각형 2칸으로 나란히, 폰은 기존처럼 세로로 쌓는다.
+                // 🖥️ 웹(넓은 화면)은 계정 추가/엑셀 등록을 정사각형 2칸으로 나란히, 폰은 기존처럼 세로로 쌓는다.
                 final bool isWide = constraints.maxWidth >= 800;
-                // 📉 계정 추가 / 엑셀 등록 칸: 기존 정사각형 크기의 25%로 축소.
-                final double formSquareSize =
-                    ((constraints.maxWidth - 20) / 2) * 0.25;
                 final double listWidth = constraints.maxWidth;
+                // 📐 학생 목록 타일과 동일한 크기를 계정 추가/엑셀 등록 칸에도 사용한다.
+                final double tileSize =
+                    ((listWidth - (isWide ? 7 : 3) * 10) / (isWide ? 8 : 4)) *
+                    1.5;
+                final double formSquareSize = tileSize;
 
                 final Widget addBoxColumn = Column(
                   crossAxisAlignment: CrossAxisAlignment.start,
@@ -760,14 +761,9 @@ class _TeacherStudentManagementPageState
                               : GridView.builder(
                                   shrinkWrap: true,
                                   physics: const NeverScrollableScrollPhysics(),
-                                  // 📈 학생 타일: 기존(8/4열 기준) 한 칸 폭보다 50% 더 큰 정사각형으로.
                                   gridDelegate:
                                       SliverGridDelegateWithMaxCrossAxisExtent(
-                                        maxCrossAxisExtent:
-                                            ((listWidth -
-                                                    (isWide ? 7 : 3) * 10) /
-                                                (isWide ? 8 : 4)) *
-                                            1.5,
+                                        maxCrossAxisExtent: tileSize,
                                         crossAxisSpacing: 10,
                                         mainAxisSpacing: 10,
                                         childAspectRatio: 1,