05/06 Phase 2: fixed error 500 Internal Server Error

app/admin/analytics/routes.py

@@ -111,4 +111,4 @@ def index():
         stats=stats,
         expiring_soon=expiring_soon,
         now=now,
-    )
+    )

app/models/platform.py

@@ -163,6 +163,9 @@ class TenantBillingHistory(db.Model):
     invoice_ref = db.Column(db.String(100), nullable=True)
     recorded_by = db.Column(db.Integer, db.ForeignKey("system_users.id"),
                             nullable=True)
+    created_at = db.Column(db.DateTime, nullable=False,
+                           default=lambda: __import__('datetime').datetime.now(
+                               __import__('datetime').timezone.utc))
 
     tenant = db.relationship("Tenant", back_populates="billing_history")
     recorder = db.relationship("SystemUser")
@@ -272,4 +275,4 @@ class JWTBlocklist(db.Model):
                            default=lambda: datetime.now(timezone.utc))
 
     def __repr__(self):
-        return f"<JWTBlocklist jti={self.jti}>"
+        return f"<JWTBlocklist jti={self.jti}>"