Update app/models/membership_plan.py

app/models/membership_plan.py

@@ -14,4 +14,5 @@ class MembershipPlan(Base):
     description = Column(Text, nullable=True)
     max_students = Column(Integer, nullable=False, default=1)  # Maximum students allowed per membership
     is_active = Column(Boolean, default=True)
+    is_default = Column(Boolean, default=False)  # Default plan shown to all students