[add]: eco models

app/models/eco/session.py

@@ -0,0 +1,18 @@
+from sqlalchemy import Column, String, DateTime, Integer
+from app.extensions import db
+
+class Session(db.Model):
+    __tablename__ = 'sessions'
+    __bind_key__ = 'eco'
+
+    id = Column(Integer, primary_key=True)
+    session_id = Column(String(50), unique=True, nullable=False)
+    customer_id = Column(String(9), nullable=True)
+    account_id = Column(String(10), nullable=True)
+    msisdn = Column(String(15), nullable=False)
+    channel = Column(String(10), nullable=False) 
+    expires_at = Column(DateTime, nullable=False)
+    status = Column(String(20), default='ACTIVE') 
+    
+    def __repr__(self):
+        return f"<Session(id={self.id}, session_id={self.session_id}, status={self.status})>"