Fix duplicate changedOrderToJob migration blocking build

Two divergent copies of this branch each independently regenerated an
EF migration named changedOrderToJob, and merging both left two files
with the same C# class name (compile error) plus an orphaned
fixedOrderCustomerID migration referencing the already-renamed orders
table. Removed the dead/unapplied migrations, committed the two
migrations already live on the shared dev DB, and added
FixJobsCustomerIdType to bring jobs.customer_id in line with the model
(text -> integer) using an explicit USING cast.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

barkmanAPI/barkDbModel.cs

@@ -65,7 +65,7 @@ public class Jobs
 public class JobItems
 {
     public int Id { get; set; }
-    public required string OrderId { get; set; }
+    public required string JobId { get; set; }
     public required string ItemId { get; set; }
     public int Quantity { get; set; }
 }