Fix incoming powder inventory: defer creation to approval, deduplicate, fix category

Three bugs fixed:

1. Wrong timing — inventory items with IsIncoming=true were auto-created during
   quote save (in QuotePricingAssemblyService). Now deferred to quote approval so
   inventory only reflects powders the shop is actually going to process.

2. Duplicate records — same powder on multiple items in one quote created multiple
   inventory records. Now grouped by PowderCatalogItemId: one record per unique
   catalog powder, all matching coats linked to the same record.

3. Wrong category — category resolution used first IsCoating=true by DisplayOrder,
   which could land items in Cerakote or other unintended categories. Now prefers
   CategoryCode==POWDER explicitly, with DisplayOrder fallback.

Changes:
- QuoteItemCoat: add PowderCatalogItemId int? — persists catalog reference at quote
  save time so the approval path knows what to create
- QuotePricingAssemblyService.BuildQuoteItemCoatsAsync: store PowderCatalogItemId
  on coat instead of calling CreateIncomingInventoryItemAsync immediately
- QuotePricingAssemblyService.CreateIncomingInventoryItemAsync: signature changed
  from (coatDto, companyId) to (catalogItemId, companyId); category lookup prefers
  POWDER code; no longer clears PowderCostPerLb on the DTO
- QuotePricingAssemblyService.EnsureIncomingInventoryForApprovedQuoteAsync: new
  public method called at approval — loads pending coats, groups by catalog ID,
  creates one inventory item per group, links all coats in each group
- IQuotePricingAssemblyService: exposes EnsureIncomingInventoryForApprovedQuoteAsync
- QuotesController.ApproveQuote: calls EnsureIncomingInventory after save
- QuotesController.ChangeQuoteStatus: calls EnsureIncomingInventory on Approved
- QuoteApprovalController: injects IQuotePricingAssemblyService; calls
  EnsureIncomingInventory in ApproveInternal (customer-facing portal path)
- InventoryController.CreateIncomingFromCatalog: same category fix (prefers POWDER)
- Migration: AddPowderCatalogItemIdToCoat (nullable int on QuoteItemCoats)
- Tests: updated AddAsIncoming test to verify deferred behavior; new deduplication test

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

src/PowderCoating.Web/Controllers/InventoryController.cs

@@ -1222,12 +1222,16 @@ public class InventoryController : Controller
 
             var companyId = _tenantContext.GetCurrentCompanyId() ?? 0;
 
-            // Find the default coating category to assign
+            // Find the default coating category to assign.
+            // Prefer the canonical "POWDER" category (CategoryCode == "POWDER") so catalog-sourced
+            // items always land in the right bucket regardless of how many IsCoating categories exist.
             var categories = await _unitOfWork.InventoryCategoryLookups.FindAsync(c => c.CompanyId == companyId);
-            var coatingCategory = categories
-                .Where(c => c.IsActive && c.IsCoating)
-                .OrderBy(c => c.DisplayOrder)
-                .FirstOrDefault();
+            var coatingCategory = categories.FirstOrDefault(c => c.IsActive && c.IsCoating
+                                      && c.CategoryCode.Equals("POWDER", StringComparison.OrdinalIgnoreCase))
+                               ?? categories
+                                      .Where(c => c.IsActive && c.IsCoating)
+                                      .OrderBy(c => c.DisplayOrder)
+                                      .FirstOrDefault();
 
             if (coatingCategory == null)
                 return Json(new { success = false, error = "No active coating category found. Please configure inventory categories first." });

src/PowderCoating.Web/Controllers/QuoteApprovalController.cs

@@ -28,6 +28,7 @@ public class QuoteApprovalController : Controller
     private readonly ILogger<QuoteApprovalController> _logger;
     private readonly IConfiguration _configuration;
     private readonly IHubContext<NotificationHub> _hub;
+    private readonly IQuotePricingAssemblyService _assemblyService;
 
     public QuoteApprovalController(
         IUnitOfWork unitOfWork,
@@ -36,7 +37,8 @@ public class QuoteApprovalController : Controller
         IStripeConnectService stripeConnect,
         ILogger<QuoteApprovalController> logger,
         IConfiguration configuration,
-        IHubContext<NotificationHub> hub)
+        IHubContext<NotificationHub> hub,
+        IQuotePricingAssemblyService assemblyService)
     {
         _unitOfWork = unitOfWork;
         _notifications = notifications;
@@ -45,6 +47,7 @@ public class QuoteApprovalController : Controller
         _logger = logger;
         _configuration = configuration;
         _hub = hub;
+        _assemblyService = assemblyService;
     }
 
     /// <summary>
@@ -177,6 +180,16 @@ public class QuoteApprovalController : Controller
 
         await _unitOfWork.CompleteAsync();
 
+        // Create incoming inventory records for catalog-sourced coats deferred from quote-save time.
+        try
+        {
+            await _assemblyService.EnsureIncomingInventoryForApprovedQuoteAsync(quote.Id, quote.CompanyId);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "EnsureIncomingInventory failed for quote {QuoteId} — continuing", quote.Id);
+        }
+
         var approveEntry = new QuoteChangeHistory
         {
             QuoteId = quote.Id,

src/PowderCoating.Web/Controllers/QuotesController.cs

@@ -2317,6 +2317,17 @@ public class QuotesController : Controller
 
             _logger.LogInformation("Quote {QuoteId} approved by user {UserId}", id, currentUser.Id);
 
+            // Create incoming inventory records for any catalog-sourced coats that were deferred
+            // from quote-save time. One record per unique powder catalog item, de-duplicated.
+            try
+            {
+                await _quotePricingAssemblyService.EnsureIncomingInventoryForApprovedQuoteAsync(id, quote.CompanyId);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogWarning(ex, "EnsureIncomingInventory failed for quote {QuoteId} — continuing", id);
+            }
+
             // Notify customer that quote is approved (only if user opted in)
             if (sendEmail)
             {
@@ -2802,6 +2813,20 @@ public class QuotesController : Controller
             await _unitOfWork.Quotes.UpdateAsync(quote);
             await _unitOfWork.SaveChangesAsync();
 
+            // When transitioning to Approved: create incoming inventory records for catalog-sourced
+            // coats that were deferred from quote-save time (one record per unique powder, deduplicated).
+            if (newStatus.StatusCode == AppConstants.StatusCodes.Quote.Approved && oldStatusCode != AppConstants.StatusCodes.Quote.Approved)
+            {
+                try
+                {
+                    await _quotePricingAssemblyService.EnsureIncomingInventoryForApprovedQuoteAsync(request.QuoteId, quote.CompanyId);
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogWarning(ex, "EnsureIncomingInventory failed for quote {QuoteId} — continuing", request.QuoteId);
+                }
+            }
+
             // Auto-create job when quote is approved — guard against double-conversion
             // (race condition: two simultaneous approval calls could both pass the oldStatusCode check)
             if (newStatus.StatusCode == AppConstants.StatusCodes.Quote.Approved && oldStatusCode != AppConstants.StatusCodes.Quote.Approved