[feat]: add models bind to eco database

app/eco/models/installment.py

@@ -0,0 +1,21 @@
+from app.eco.enums.installment_status import InstallmentStatus
+from sqlalchemy import Column, String, Date, Numeric, ForeignKey, Enum, Integer, DateTime
+from app.extensions import db
+import enum
+
+class Installment(db.Model):
+    __tablename__ = 'installments'
+    __bind_key__ = 'eco'
+
+
+    id = Column(Integer, primary_key=True)
+    loan_id = Column(Integer, nullable=False)
+    installment_number = Column(Integer, nullable=False)
+    due_date = Column(Date, nullable=False)
+    amount = Column(Numeric(12, 2), nullable=False)
+    paid_amount = Column(Numeric(12, 2), default=0.00)
+    status = Column(Enum(InstallmentStatus), default=InstallmentStatus.PENDING)
+    penalty_amount = Column(Numeric(12, 2), default=0.00)
+    
+    def __repr__(self):
+        return f"<Installment(id={self.id}, loan_id={self.loan_id}, status={self.status})>"