Propagate catalog price to inventory and quote at current price

Quotes now reflect the current catalog price instead of a tenant's stale
typed-in cost, without disturbing accounting.

- InventoryItem gains CatalogReferencePrice + CatalogPriceUpdatedAt: the
  QUOTING price (current replacement cost), kept separate from UnitCost/
  AverageCost (the cost basis that drives valuation/COGS).
- The catalog sync (PowderCatalogUpsertService.PropagateToLinkedInventoryAsync,
  run at the end of every upsert) refreshes linked inventory items with the
  catalog's current price and product data (description, cure, SDS/TDS, color
  families, coverage, SG, transfer eff, requires-clear-coat). It NEVER touches
  cost, quantity, notes, image, location, or stock levels, and never nulls a
  tenant value with a catalog null. EF persists only actual changes.
- CatalogReferencePrice is also set at link time (catalog receive, incoming-
  from-catalog, identity match on create) so a freshly added powder quotes at
  the current price immediately.
- Pricing now uses CatalogReferencePrice ?? UnitCost: the quote/job powder
  pickers and PricingCalculationService (in-stock usage and powder-to-order
  billing). Falls back to UnitCost for non-catalog/manual powders, so nothing
  regresses. One current price for the whole quantity — no on-hand/to-order
  split. Per-coat snapshot still locks the price at quote creation.

Tests: propagation updates reference price + specs but not cost/qty/notes/
image, and skips a $0 catalog price. Full suite 276 green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/PowderCoating.UnitTests/PowderCatalogPropagationTests.cs

@@ -0,0 +1,145 @@
+using System.Security.Claims;
+using Microsoft.AspNetCore.Http;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+using Moq;
+using PowderCoating.Core.Entities;
+using PowderCoating.Infrastructure.Data;
+using PowderCoating.Infrastructure.Repositories;
+using PowderCoating.Infrastructure.Services;
+
+namespace PowderCoating.UnitTests;
+
+/// <summary>
+/// Verifies that catalog sync propagation updates a linked inventory item's quoting reference price
+/// and product data, while never touching the tenant-owned cost basis, quantity, notes, or image.
+/// </summary>
+public class PowderCatalogPropagationTests
+{
+    [Fact]
+    public async Task Propagate_UpdatesReferencePriceAndSpecs_ButNotCostQuantityNotesOrImage()
+    {
+        await using var context = CreateContext();
+
+        var catalog = new PowderCatalogItem
+        {
+            VendorName = "Columbia Coatings",
+            Sku = "CS1693053",
+            ColorName = "Joker Jewel",
+            Source = "Columbia Coatings API",
+            UnitPrice = 28m,                // new catalog price
+            SdsUrl = "https://cc/sds.pdf",
+            TdsUrl = "https://cc/tds.pdf",
+            CureTemperatureF = 400m,
+            CureTimeMinutes = 10,
+            ColorFamilies = "Green,Purple",
+        };
+        context.PowderCatalogItems.Add(catalog);
+        await context.SaveChangesAsync();
+
+        var inv = new InventoryItem
+        {
+            CompanyId = 1,
+            SKU = "POWD-2606-0001",
+            Name = "Joker Jewel",
+            PowderCatalogItemId = catalog.Id,
+            UnitCost = 20m,                 // what they actually paid
+            AverageCost = 20m,
+            LastPurchasePrice = 20m,
+            QuantityOnHand = 5m,
+            Notes = "keep my note",
+            ImageUrl = "my-own-photo.jpg",
+            CatalogReferencePrice = null,   // not yet set
+        };
+        context.InventoryItems.Add(inv);
+        await context.SaveChangesAsync();
+
+        var service = new PowderCatalogUpsertService(
+            new UnitOfWork(context),
+            Mock.Of<ILogger<PowderCatalogUpsertService>>());
+
+        var updated = await service.PropagateToLinkedInventoryAsync();
+
+        Assert.Equal(1, updated);
+
+        var refreshed = await context.InventoryItems.FindAsync(inv.Id);
+        Assert.NotNull(refreshed);
+
+        // Quoting reference price + product data refreshed from the catalog.
+        Assert.Equal(28m, refreshed!.CatalogReferencePrice);
+        Assert.NotNull(refreshed.CatalogPriceUpdatedAt);
+        Assert.Equal("https://cc/sds.pdf", refreshed.SdsUrl);
+        Assert.Equal("https://cc/tds.pdf", refreshed.TdsUrl);
+        Assert.Equal(400m, refreshed.CureTemperatureF);
+        Assert.Equal("Green,Purple", refreshed.ColorFamilies);
+
+        // Tenant-owned fields untouched.
+        Assert.Equal(20m, refreshed.UnitCost);
+        Assert.Equal(20m, refreshed.AverageCost);
+        Assert.Equal(20m, refreshed.LastPurchasePrice);
+        Assert.Equal(5m, refreshed.QuantityOnHand);
+        Assert.Equal("keep my note", refreshed.Notes);
+        Assert.Equal("my-own-photo.jpg", refreshed.ImageUrl);
+    }
+
+    [Fact]
+    public async Task Propagate_DoesNotSetReferencePrice_WhenCatalogPriceIsZero()
+    {
+        await using var context = CreateContext();
+
+        var catalog = new PowderCatalogItem
+        {
+            VendorName = "Columbia Coatings",
+            Sku = "X1",
+            ColorName = "No Price",
+            Source = "Columbia Coatings API",
+            UnitPrice = 0m, // unknown price — must not wipe quoting with $0
+        };
+        context.PowderCatalogItems.Add(catalog);
+        await context.SaveChangesAsync();
+
+        var inv = new InventoryItem
+        {
+            CompanyId = 1,
+            SKU = "POWD-2606-0002",
+            Name = "No Price",
+            PowderCatalogItemId = catalog.Id,
+            UnitCost = 15m,
+            CatalogReferencePrice = null,
+        };
+        context.InventoryItems.Add(inv);
+        await context.SaveChangesAsync();
+
+        var service = new PowderCatalogUpsertService(
+            new UnitOfWork(context),
+            Mock.Of<ILogger<PowderCatalogUpsertService>>());
+
+        await service.PropagateToLinkedInventoryAsync();
+
+        var refreshed = await context.InventoryItems.FindAsync(inv.Id);
+        Assert.Null(refreshed!.CatalogReferencePrice); // stays null -> quoting falls back to UnitCost
+    }
+
+    private static ApplicationDbContext CreateContext()
+    {
+        var options = new DbContextOptionsBuilder<ApplicationDbContext>()
+            .UseInMemoryDatabase(Guid.NewGuid().ToString())
+            .Options;
+
+        var identity = new ClaimsIdentity([new Claim(ClaimTypes.Role, "SuperAdmin")], "Test");
+        var principal = new ClaimsPrincipal(identity);
+
+        byte[]? noBytes = null;
+        var sessionMock = new Mock<ISession>();
+        sessionMock.Setup(s => s.TryGetValue(It.IsAny<string>(), out noBytes)).Returns(false);
+
+        var httpContextMock = new Mock<HttpContext>();
+        httpContextMock.SetupGet(c => c.User).Returns(principal);
+        httpContextMock.SetupGet(c => c.Session).Returns(sessionMock.Object);
+
+        var accessor = new Mock<IHttpContextAccessor>();
+        accessor.SetupGet(a => a.HttpContext).Returns(httpContextMock.Object);
+
+        return new ApplicationDbContext(options, accessor.Object, null!);
+    }
+}