feat(settings): clean academic setup buttons and rename screen to Academic & Class Management

- Update screen, settings card, and dashboard titles to 'Academic & Class Management'

- Clean and balance Academic Structure toolbar for mobile and desktop

- Remove redundant buttons on section cards in favor of interactive adviser chip

- Modernize teacher action button to OutlinedButton.icon 'Sections'

- Add responsive bulk academic structure import support across backend and frontend

frontend/lib/domain/entities/setup_models.dart

@@ -30,6 +30,16 @@ class SectionModel {
   final int gradeLevel;
   final int? academicYearId;
   final String? academicYearRange;
+  final int? teacherId;
+  final String? teacherFirstName;
+  final String? teacherLastName;
+
+  String? get teacherFullName {
+    if (teacherLastName != null && teacherFirstName != null) {
+      return '$teacherLastName, $teacherFirstName';
+    }
+    return teacherFirstName ?? teacherLastName;
+  }
 
   SectionModel({
     required this.id,
@@ -37,6 +47,9 @@ class SectionModel {
     required this.gradeLevel,
     this.academicYearId,
     this.academicYearRange,
+    this.teacherId,
+    this.teacherFirstName,
+    this.teacherLastName,
   });
 
   factory SectionModel.fromJson(Map<String, dynamic> json) {
@@ -48,6 +61,11 @@ class SectionModel {
           ? (json['academic_year_id'] as num).toInt()
           : null,
       academicYearRange: json['academic_year_range'] as String?,
+      teacherId: json['teacher_id'] != null
+          ? (json['teacher_id'] as num).toInt()
+          : null,
+      teacherFirstName: json['teacher_first_name'] as String?,
+      teacherLastName: json['teacher_last_name'] as String?,
     );
   }
 }

frontend/lib/domain/repositories/setup_repository.dart

@@ -167,6 +167,7 @@ class SetupRepository {
     required String name,
     required int gradeLevel,
     required int academicYearId,
+    int? teacherId,
   }) async {
     try {
       final options = await _getAuthOptions();
@@ -177,6 +178,7 @@ class SetupRepository {
           'name': name,
           'gradeLevel': gradeLevel,
           'academicYearId': academicYearId,
+          if (teacherId != null) 'teacherId': teacherId,
         },
       );
     } on DioException catch (e) {
@@ -208,6 +210,7 @@ class SetupRepository {
     required String name,
     required int gradeLevel,
     required int academicYearId,
+    int? teacherId,
   }) async {
     try {
       final options = await _getAuthOptions();
@@ -218,6 +221,7 @@ class SetupRepository {
           'name': name,
           'gradeLevel': gradeLevel,
           'academicYearId': academicYearId,
+          'teacherId': teacherId,
         },
       );
     } on DioException catch (e) {
@@ -225,6 +229,22 @@ class SetupRepository {
     }
   }
 
+  Future<void> setSectionAdviser({
+    required int sectionId,
+    int? teacherId,
+  }) async {
+    try {
+      final options = await _getAuthOptions();
+      await _dio.put(
+        '/setup/sections/$sectionId/adviser',
+        options: options,
+        data: {'teacherId': teacherId},
+      );
+    } on DioException catch (e) {
+      throw Exception(_extractErrorMessage(e, 'Failed to update section adviser.'));
+    }
+  }
+
   Future<void> deleteSection(int id) async {
     try {
       final options = await _getAuthOptions();