Add manufacturer to Log Material item combobox

Shows manufacturer name as muted secondary text in each dropdown row
and includes it in the search filter, so users can find a powder by
brand when multiple items share a similar name.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/PowderCoating.Web/Controllers/JobsController.cs

@@ -501,7 +501,7 @@ public class JobsController : Controller
             // Inventory items for the manual log-material modal
             var inventoryItemsForModal = (await _unitOfWork.InventoryItems.GetAllAsync())
                 .OrderBy(i => i.Name)
-                .Select(i => new { i.Id, i.Name, i.UnitOfMeasure, i.QuantityOnHand })
+                .Select(i => new { i.Id, i.Name, i.Manufacturer, i.UnitOfMeasure, i.QuantityOnHand })
                 .ToList();
             ViewBag.InventoryItemsForModal = System.Text.Json.JsonSerializer.Serialize(
                 inventoryItemsForModal,