Feat: build tribe and student model

backend/model/student.py

@@ -0,0 +1,28 @@
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+
+
+@dataclass
+class Tribe:
+    name: str
+    level: str
+    students: list[Student] = field(default_factory=list)
+
+    def register_student(self, student: Student):
+        self.students.append(student)
+
+
+@dataclass
+class Student:
+    def __init__(self, id: str, name: str, tribe: Tribe) -> None:
+        self.id = id
+        self.name = name
+        self.tribe = tribe
+
+        self.tribe.register_student(self)
+
+    def __eq__(self, other: object) -> bool:
+        if isinstance(other, Student):
+            return self.id == other.id
+        return False