// Attendance Model
studentId: ObjectId, amount: 5000, paid: 4500, dueDate: "2025-05-10"
// Fee Model
studentId: ObjectId, date: "2025-03-20", status: "present" // present, absent, late
name: "Riya Sharma", rollNo: 101, class: "10", section: "A", parentEmail: "parent@email.com", admissionYear: 2024
