feat: added liquidation model

margin_app/app/models/__init__.py

@@ -4,3 +4,4 @@
 
 from app.models.base import BaseModel
 from app.models.user import User
+from app.models.liquidation import Liquidation

margin_app/app/models/liquidation.py

@@ -0,0 +1,30 @@
+"""
+Liquidation model
+"""
+
+import uuid
+
+from datetime import datetime
+from decimal import Decimal
+from sqlalchemy import DateTime, String, ForeignKey
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import Mapped, mapped_column
+from app.models.base import BaseModel
+
+class Liquidation(BaseModel):
+    """
+    Liquidation Model
+    Columns:
+        margin_position_id: Foreign key referencing MarginPosition.id.
+        bonus_amount: The amount of bonus given during liquidation.
+        bonus_token: The token in which the bonus is given.
+        created_at: Timestamp when the liquidation was created.
+    """
+
+    margin_position_id: Mapped[UUID] = mapped_column(
+        UUID(as_uuid=True), 
+        ForeignKey("margin_position.id"), 
+        nullable=False
+    )
+    bonus_amount: Mapped[Decimal] = mapped_column(nullable=False)
+    bonus_token: Mapped[str] = mapped_column(String, nullable=False)