[add]: Database connection and migrations

app/models/offer.py

@@ -0,0 +1,12 @@
+from datetime import datetime
+from app import db
+
+class Offer(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    amount = db.Column(db.Float, nullable=False)
+    interest_rate = db.Column(db.Float, nullable=False)
+    created_at = db.Column(db.DateTime, default=datetime.utcnow)
+    updated_at = db.Column(db.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
+
+    def __repr__(self):
+        return f'<LoanOffer {self.id}>'