Fix customer lookup: treat Order.UserID=0 as NULL

COALESCE treats 0 as valid, so Order.UserID=0 was matching User 0
(Payfrit Network) instead of falling back to Task.UserID.
Use NULLIF to convert 0 to NULL before the fallback.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

api/tasks/getDetails.cfm

@@ -74,7 +74,7 @@
     LEFT JOIN Businesses b ON b.ID = t.BusinessID
     LEFT JOIN ServicePoints sp ON sp.ID = o.ServicePointID
     LEFT JOIN ServicePoints tsp ON tsp.ID = t.ServicePointID
-    LEFT JOIN Users u ON u.ID = COALESCE(o.UserID, t.UserID)
+    LEFT JOIN Users u ON u.ID = COALESCE(NULLIF(o.UserID, 0), t.UserID)
     WHERE t.ID = ?
   ", [ { value = TaskID, cfsqltype = "cf_sql_integer" } ], { datasource = "payfrit" })>