전체 학생 목록에 학번 검색 + 학년 필터, 1학년부터 정렬 추가

목록을 학년 오름차순(1→2→3, 미배정은 맨 뒤)으로 정렬하고, 학번으로
검색하는 입력창과 전체/1학년/2학년/3학년 필터 칩을 추가.

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

lib/function/teacher_student_management_controller.dart

@@ -38,8 +38,42 @@ class TeacherStudentManagementController extends ChangeNotifier {
 
   List<dynamic> _students = [];
   bool _isLoadingStudents = true;
+  String _searchQuery = '';
+  int? _gradeFilter; // null = 전체
   List<dynamic> get students => _students;
   bool get isLoadingStudents => _isLoadingStudents;
+  String get searchQuery => _searchQuery;
+  int? get gradeFilter => _gradeFilter;
+
+  /// 🔍 학번 검색 + 학년 필터를 적용하고, 학년 오름차순(1→2→3, 미배정은 맨 뒤)으로
+  /// 정렬한 목록. 화면에는 이 목록을 그린다.
+  List<dynamic> get filteredStudents {
+    final query = _searchQuery.trim();
+    final filtered = _students.where((s) {
+      if (_gradeFilter != null && s['grade'] != _gradeFilter) return false;
+      if (query.isEmpty) return true;
+      return s['id'].toString().contains(query);
+    }).toList();
+    filtered.sort((a, b) {
+      final ga = a['grade'] as int?;
+      final gb = b['grade'] as int?;
+      if (ga == null && gb == null) return 0;
+      if (ga == null) return 1;
+      if (gb == null) return -1;
+      return ga.compareTo(gb);
+    });
+    return filtered;
+  }
+
+  void setSearchQuery(String query) {
+    _searchQuery = query;
+    notifyListeners();
+  }
+
+  void setGradeFilter(int? grade) {
+    _gradeFilter = grade;
+    notifyListeners();
+  }
 
   Future<void> init() => fetchStudents();
 

lib/ui/teacher_student_management_page.dart

@@ -358,6 +358,20 @@ class _TeacherStudentManagementPageState
   }
 
   // 🏷️ 섹션 제목 (색 인디케이터 바 + 텍스트).
+  Widget _gradeFilterChip(int? grade, String label) {
+    final bool selected = _controller.gradeFilter == grade;
+    return ChoiceChip(
+      label: Text(label),
+      selected: selected,
+      onSelected: (_) => _controller.setGradeFilter(grade),
+      selectedColor: AppPalette.ink,
+      labelStyle: TextStyle(
+        color: selected ? Colors.white : AppPalette.ink,
+        fontWeight: FontWeight.bold,
+      ),
+    );
+  }
+
   Widget _sectionTitle(String text, {Color color = AppPalette.ink}) {
     return Row(
       children: [
@@ -753,6 +767,42 @@ class _TeacherStudentManagementPageState
                             ),
                           ),
                           const SizedBox(height: 12),
+                          Row(
+                            children: [
+                              Expanded(
+                                child: TextField(
+                                  onChanged: _controller.setSearchQuery,
+                                  keyboardType: TextInputType.number,
+                                  decoration: InputDecoration(
+                                    hintText: '학번으로 검색',
+                                    prefixIcon: const Icon(
+                                      Icons.search_rounded,
+                                    ),
+                                    filled: true,
+                                    fillColor: AppPalette.paper,
+                                    contentPadding: const EdgeInsets.symmetric(
+                                      vertical: 0,
+                                    ),
+                                    border: OutlineInputBorder(
+                                      borderRadius: BorderRadius.circular(12),
+                                      borderSide: BorderSide(
+                                        color: AppPalette.sage,
+                                      ),
+                                    ),
+                                  ),
+                                ),
+                              ),
+                              const SizedBox(width: 12),
+                              _gradeFilterChip(null, '전체'),
+                              const SizedBox(width: 6),
+                              _gradeFilterChip(1, '1학년'),
+                              const SizedBox(width: 6),
+                              _gradeFilterChip(2, '2학년'),
+                              const SizedBox(width: 6),
+                              _gradeFilterChip(3, '3학년'),
+                            ],
+                          ),
+                          const SizedBox(height: 12),
                           _controller.isLoadingStudents
                               ? const Padding(
                                   padding: EdgeInsets.symmetric(vertical: 40),
@@ -760,13 +810,19 @@ class _TeacherStudentManagementPageState
                                     child: CircularProgressIndicator(),
                                   ),
                                 )
-                              : _controller.students.isEmpty
+                              : _controller.filteredStudents.isEmpty
-                              ? const Padding(
+                              ? Padding(
-                                  padding: EdgeInsets.symmetric(vertical: 24),
+                                  padding: const EdgeInsets.symmetric(
+                                    vertical: 24,
+                                  ),
                                   child: Center(
                                     child: Text(
-                                      '가입된 학생 계정이 없습니다.',
+                                      _controller.students.isEmpty
-                                      style: TextStyle(color: Colors.grey),
+                                          ? '가입된 학생 계정이 없습니다.'
+                                          : '검색/필터 조건에 맞는 학생이 없습니다.',
+                                      style: const TextStyle(
+                                        color: Colors.grey,
+                                      ),
                                     ),
                                   ),
                                 )
@@ -781,10 +837,11 @@ class _TeacherStudentManagementPageState
                                         crossAxisSpacing: 12,
                                         mainAxisSpacing: 12,
                                       ),
-                                  itemCount: _controller.students.length,
+                                  itemCount:
+                                      _controller.filteredStudents.length,
                                   itemBuilder: (context, index) =>
                                       _buildStudentTile(
-                                        _controller.students[index],
+                                        _controller.filteredStudents[index],
                                       ),
                                 ),
                         ],