feat(student): add Student class

app/src/main/java/ru/project/student/Student.java

@@ -0,0 +1,38 @@
+package ru.project.student;
+
+public class Student {
+    private final String groupNumber;
+    private final double averageGrade;
+    private final String recordBookNumber;
+
+    Student(String groupNumber, double averageGrade, String recordBookNumber) {
+        if (groupNumber == null || groupNumber.isBlank()) {
+            throw new IllegalArgumentException("Group number cannot be empty");
+        }
+        if (averageGrade < 0.0 || averageGrade > 5.0) {
+            throw new IllegalArgumentException("Average grade must be between 0.0 and 5.0");
+        }
+        if (recordBookNumber == null || recordBookNumber.isBlank()) {
+            throw new IllegalArgumentException("Record book number cannot be empty");
+        }
+        this.groupNumber = groupNumber;
+        this.averageGrade = averageGrade;
+        this.recordBookNumber = recordBookNumber;
+    }
+
+    public String getGroupNumber() {
+        return groupNumber;
+    }
+
+    public double getAverageGrade() {
+        return averageGrade;
+    }
+
+    public String getRecordBookNumber() {
+        return recordBookNumber;
+    }
+@Override
+    public String toString(){
+        return "Student ="+groupNumber+
+}
+}