feat(sync): add academic data reset tool, configurable sheets URL and fix sync timeout

backend/app/models/__init__.py

@@ -10,6 +10,7 @@ from .role import Role, Permission, SYSTEM_MODULES
 from .milestone import MilestoneType, AcademicMilestone, BASE_MILESTONE_TYPES
 from .audit_log import AuditLog
 from .enrollment import StudentEnrollment
+from .setting import SystemSetting
 
 __all__ = [
     'User',
@@ -31,5 +32,6 @@ __all__ = [
     'AcademicMilestone',
     'BASE_MILESTONE_TYPES',
     'AuditLog',
-    'StudentEnrollment'
+    'StudentEnrollment',
+    'SystemSetting'
 ]