training fix. add global settings

backend/models/Settings.py

@@ -0,0 +1,21 @@
+from database.database import db
+
+class Settings(db.Model):
+    __tablename__ = 'settings'
+    
+    id = db.Column(db.Integer, primary_key=True)
+    key = db.Column(db.String(255), unique=True, nullable=False)
+    value = db.Column(db.Text, nullable=True)
+    description = db.Column(db.String(500), nullable=True)
+    created_at = db.Column(db.DateTime, server_default=db.func.now())
+    updated_at = db.Column(db.DateTime, server_default=db.func.now(), onupdate=db.func.now())
+    
+    def to_dict(self):
+        return {
+            'id': self.id,
+            'key': self.key,
+            'value': self.value,
+            'description': self.description,
+            'created_at': self.created_at.isoformat() if self.created_at else None,
+            'updated_at': self.updated_at.isoformat() if self.updated_at else None
+        }