Fix time entry workers, powder usage logging, inventory edit, and mojibake

- JobTimeEntry: migrate to UserId/UserDisplayName; make ShopWorkerId nullable
  (migration MigrateTimeEntriesToUserId)
- Log Time modal: populate worker dropdown from Identity users instead of
  ShopWorkers; fix ShopMobile view same issue
- Inventory Ledger: scan-based JobUsage transactions now appear in
  Powder Usage By Job tab (synthesized from InventoryTransaction)
- Inventory Ledger: add Edit button for JobUsage transactions; new
  GetUsageForEdit + EditUsageTransaction endpoints; inventory-ledger.js
- InventoryTransactionRepository: include Job.Customer for ledger queries
- InventoryAiLookupService: handle JSON-LD @graph wrapper (Columbia
  Coatings / WooCommerce+Yoast); add HTML price snippet fallback
- Fix mojibake in 9 views: â†' → →, âœ" → ✓, âš  → ⚠

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

src/PowderCoating.Web/Views/Jobs/ShopMobile.cshtml

@@ -1,9 +1,7 @@
 @model List<PowderCoating.Application.DTOs.Job.JobDailyPriorityDto>
-@using PowderCoating.Core.Entities
-
 @{
     Layout = null;
-    var workers = ViewBag.Workers as List<ShopWorker> ?? new();
+    var workers = (ViewBag.Workers as IEnumerable<dynamic>) ?? Array.Empty<dynamic>();
     var currentWorkerId = ViewBag.CurrentWorkerId as string;
     var allStatuses = ViewBag.AllStatuses as List<JobStatusLookup> ?? new();
     var activeCount = Model.Count;