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/Migrations/BarkContextModelSnapshot.cs

@@ -159,15 +159,15 @@ namespace barkmanapi.Migrations
                         .HasColumnType("text")
                         .HasColumnName("item_id");
 
+                    b.Property<string>("JobId")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("job_id");
+
                     b.Property<int?>("JobsId")
                         .HasColumnType("integer")
                         .HasColumnName("jobs_id");
 
-                    b.Property<string>("OrderId")
-                        .IsRequired()
-                        .HasColumnType("text")
-                        .HasColumnName("order_id");
-
                     b.Property<int>("Quantity")
                         .HasColumnType("integer")
                         .HasColumnName("quantity");