Add Columbia Coatings catalog integration schema fields

Phase 1a of the Columbia Coatings API integration. Adds the persisted
fields the sync/mapper will need, ahead of the client and sync service:

PowderCatalogItem:
- Category: our product category (e.g. "Powder Additives" for gram-sold
  pigments) derived from vendor taxonomy at import, not stored raw.
- Source: provenance (e.g. "Columbia Coatings API"), kept separate from
  VendorName (= derived manufacturer) so a distributor's right-to-delete
  can purge by feed regardless of manufacturer.
- ChemistryType: resin chemistry (Polyester/TGIC/Epoxy/...), distinct
  from Finish.
- MilThickness: recommended film build as vendor free text.
- CureScheduleText: raw cure schedule verbatim (formats vary widely).
- CureCurvesJson: all parsed cure curves, so alternate low-temp curves
  are preserved for heat-sensitive substrates, not just the primary.
- FormulationChanges: vendor reformulation log; a signal cure specs may
  have changed.

InventoryItem:
- PowderCatalogItemId: loose link to the catalog row (matches the
  QuoteItemCoat pattern) so inventory detail can show manufacturer-level
  status (e.g. discontinued/cannot reorder) and future change flags.
  Nulled, never cascaded, when source catalog data is purged.

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

src/PowderCoating.Core/Entities/InventoryItem.cs

@@ -31,6 +31,15 @@ public class InventoryItem : BaseEntity
     public string? SdsUrl { get; set; }         // Safety Data Sheet URL (from powder catalog or manual entry)
     public string? TdsUrl { get; set; }         // Technical Data Sheet URL (from powder catalog or manual entry)
 
+    /// <summary>
+    /// Optional link to the platform powder catalog record this item was created from.
+    /// Populated when an item is added via the catalog lookup, or back-filled by Manufacturer+SKU.
+    /// Lets the inventory detail screen surface manufacturer-level status (e.g. "discontinued by
+    /// manufacturer — cannot reorder") and future price/reformulation change flags. Nulled — not
+    /// cascaded — if the source catalog data is purged (the shop's own stock record must survive).
+    /// </summary>
+    public int? PowderCatalogItemId { get; set; }
+
     // Sample Panel Tracking (coating category items only)
     public bool HasSamplePanel { get; set; } = false;
 

src/PowderCoating.Core/Entities/PowderCatalogItem.cs

@@ -40,9 +40,30 @@ public class PowderCatalogItem
     /// <summary>Cure hold time at cure temperature, in minutes.</summary>
     public int? CureTimeMinutes { get; set; }
 
+    /// <summary>
+    /// Raw cure schedule text exactly as supplied by the vendor — e.g. "10 minutes @ 400°F".
+    /// Preserved verbatim because vendor formats vary wildly and some carry application notes
+    /// that don't reduce to a single temp/time pair (partial cures, clear-coat steps).
+    /// </summary>
+    public string? CureScheduleText { get; set; }
+
+    /// <summary>
+    /// All parsed cure curves as JSON — e.g. [{"tempF":400,"minutes":10},{"tempF":350,"minutes":20}].
+    /// Many powders list alternate lower-temperature curves; these matter for heat-sensitive
+    /// substrates that cannot take the standard 400°F cure, so we keep every curve, not just the
+    /// primary one in <see cref="CureTemperatureF"/>/<see cref="CureTimeMinutes"/>.
+    /// </summary>
+    public string? CureCurvesJson { get; set; }
+
     /// <summary>Finish type — e.g. Gloss, Matte, Satin, Metallic, Texture.</summary>
     public string? Finish { get; set; }
 
+    /// <summary>Resin chemistry — e.g. "Polyester", "TGIC", "Epoxy", "Hybrid". Distinct from <see cref="Finish"/>.</summary>
+    public string? ChemistryType { get; set; }
+
+    /// <summary>Recommended film build (mil thickness) as free text from the vendor — e.g. "2.0-3.0 Mils".</summary>
+    public string? MilThickness { get; set; }
+
     /// <summary>Comma-separated color family tags — e.g. "Blue,Purple".</summary>
     public string? ColorFamilies { get; set; }
 
@@ -60,6 +81,29 @@ public class PowderCatalogItem
 
     // ── Catalog management ────────────────────────────────────────────────
 
+    /// <summary>
+    /// Our internal product category — e.g. "Powder Additives" for pigments/additives that are
+    /// sold by weight in grams and mixed into clear rather than sprayed as a standalone powder.
+    /// Null/empty for standard powders. Derived at import from the vendor's taxonomy, NOT stored
+    /// from their raw category list.
+    /// </summary>
+    public string? Category { get; set; }
+
+    /// <summary>
+    /// Provenance of this record — e.g. "Columbia Coatings API". Kept SEPARATE from
+    /// <see cref="VendorName"/> (which holds the derived manufacturer) so we can honor a
+    /// distributor's right-to-delete by purging every record that came from their feed,
+    /// regardless of which manufacturer made the product.
+    /// </summary>
+    public string? Source { get; set; }
+
+    /// <summary>
+    /// Reformulation history as supplied by the vendor — e.g. "Formulation Change: 05/22/26".
+    /// Not a reliable modified-date (free text, reformulations only) but a useful signal that a
+    /// product's formula — and therefore its cure specs — may have changed.
+    /// </summary>
+    public string? FormulationChanges { get; set; }
+
     /// <summary>True when the vendor has discontinued this product. Kept for historical lookups.</summary>
     public bool IsDiscontinued { get; set; } = false;
 

src/PowderCoating.Infrastructure/Migrations/20260617142130_AddColumbiaCatalogIntegrationFields.cs

@@ -0,0 +1,141 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace PowderCoating.Infrastructure.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddColumbiaCatalogIntegrationFields : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "Category",
+                table: "PowderCatalogItems",
+                type: "nvarchar(max)",
+                nullable: true);
+
+            migrationBuilder.AddColumn<string>(
+                name: "ChemistryType",
+                table: "PowderCatalogItems",
+                type: "nvarchar(max)",
+                nullable: true);
+
+            migrationBuilder.AddColumn<string>(
+                name: "CureCurvesJson",
+                table: "PowderCatalogItems",
+                type: "nvarchar(max)",
+                nullable: true);
+
+            migrationBuilder.AddColumn<string>(
+                name: "CureScheduleText",
+                table: "PowderCatalogItems",
+                type: "nvarchar(max)",
+                nullable: true);
+
+            migrationBuilder.AddColumn<string>(
+                name: "FormulationChanges",
+                table: "PowderCatalogItems",
+                type: "nvarchar(max)",
+                nullable: true);
+
+            migrationBuilder.AddColumn<string>(
+                name: "MilThickness",
+                table: "PowderCatalogItems",
+                type: "nvarchar(max)",
+                nullable: true);
+
+            migrationBuilder.AddColumn<string>(
+                name: "Source",
+                table: "PowderCatalogItems",
+                type: "nvarchar(max)",
+                nullable: true);
+
+            migrationBuilder.AddColumn<int>(
+                name: "PowderCatalogItemId",
+                table: "InventoryItems",
+                type: "int",
+                nullable: true);
+
+            migrationBuilder.UpdateData(
+                table: "PricingTiers",
+                keyColumn: "Id",
+                keyValue: 1,
+                column: "CreatedAt",
+                value: new DateTime(2026, 6, 17, 14, 21, 27, 126, DateTimeKind.Utc).AddTicks(6644));
+
+            migrationBuilder.UpdateData(
+                table: "PricingTiers",
+                keyColumn: "Id",
+                keyValue: 2,
+                column: "CreatedAt",
+                value: new DateTime(2026, 6, 17, 14, 21, 27, 126, DateTimeKind.Utc).AddTicks(6651));
+
+            migrationBuilder.UpdateData(
+                table: "PricingTiers",
+                keyColumn: "Id",
+                keyValue: 3,
+                column: "CreatedAt",
+                value: new DateTime(2026, 6, 17, 14, 21, 27, 126, DateTimeKind.Utc).AddTicks(6652));
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "Category",
+                table: "PowderCatalogItems");
+
+            migrationBuilder.DropColumn(
+                name: "ChemistryType",
+                table: "PowderCatalogItems");
+
+            migrationBuilder.DropColumn(
+                name: "CureCurvesJson",
+                table: "PowderCatalogItems");
+
+            migrationBuilder.DropColumn(
+                name: "CureScheduleText",
+                table: "PowderCatalogItems");
+
+            migrationBuilder.DropColumn(
+                name: "FormulationChanges",
+                table: "PowderCatalogItems");
+
+            migrationBuilder.DropColumn(
+                name: "MilThickness",
+                table: "PowderCatalogItems");
+
+            migrationBuilder.DropColumn(
+                name: "Source",
+                table: "PowderCatalogItems");
+
+            migrationBuilder.DropColumn(
+                name: "PowderCatalogItemId",
+                table: "InventoryItems");
+
+            migrationBuilder.UpdateData(
+                table: "PricingTiers",
+                keyColumn: "Id",
+                keyValue: 1,
+                column: "CreatedAt",
+                value: new DateTime(2026, 6, 14, 1, 21, 46, 131, DateTimeKind.Utc).AddTicks(4191));
+
+            migrationBuilder.UpdateData(
+                table: "PricingTiers",
+                keyColumn: "Id",
+                keyValue: 2,
+                column: "CreatedAt",
+                value: new DateTime(2026, 6, 14, 1, 21, 46, 131, DateTimeKind.Utc).AddTicks(4196));
+
+            migrationBuilder.UpdateData(
+                table: "PricingTiers",
+                keyColumn: "Id",
+                keyValue: 3,
+                column: "CreatedAt",
+                value: new DateTime(2026, 6, 14, 1, 21, 46, 131, DateTimeKind.Utc).AddTicks(4197));
+        }
+    }
+}

src/PowderCoating.Infrastructure/Migrations/ApplicationDbContextModelSnapshot.cs

@@ -4173,6 +4173,9 @@ namespace PowderCoating.Infrastructure.Migrations
                     b.Property<string>("Notes")
                         .HasColumnType("nvarchar(max)");
 
+                    b.Property<int?>("PowderCatalogItemId")
+                        .HasColumnType("int");
+
                     b.Property<int?>("PrimaryVendorId")
                         .HasColumnType("int");
 
@@ -6936,6 +6939,12 @@ namespace PowderCoating.Infrastructure.Migrations
                     b.Property<string>("ApplicationGuideUrl")
                         .HasColumnType("nvarchar(max)");
 
+                    b.Property<string>("Category")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("ChemistryType")
+                        .HasColumnType("nvarchar(max)");
+
                     b.Property<string>("ColorFamilies")
                         .HasColumnType("nvarchar(max)");
 
@@ -6949,6 +6958,12 @@ namespace PowderCoating.Infrastructure.Migrations
                     b.Property<DateTime>("CreatedAt")
                         .HasColumnType("datetime2");
 
+                    b.Property<string>("CureCurvesJson")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("CureScheduleText")
+                        .HasColumnType("nvarchar(max)");
+
                     b.Property<decimal?>("CureTemperatureF")
                         .HasColumnType("decimal(18,2)");
 
@@ -6961,6 +6976,9 @@ namespace PowderCoating.Infrastructure.Migrations
                     b.Property<string>("Finish")
                         .HasColumnType("nvarchar(max)");
 
+                    b.Property<string>("FormulationChanges")
+                        .HasColumnType("nvarchar(max)");
+
                     b.Property<string>("ImageUrl")
                         .HasColumnType("nvarchar(max)");
 
@@ -6973,6 +6991,9 @@ namespace PowderCoating.Infrastructure.Migrations
                     b.Property<DateTime?>("LastSyncedAt")
                         .HasColumnType("datetime2");
 
+                    b.Property<string>("MilThickness")
+                        .HasColumnType("nvarchar(max)");
+
                     b.Property<string>("PriceTiersJson")
                         .HasColumnType("nvarchar(max)");
 
@@ -6989,6 +7010,9 @@ namespace PowderCoating.Infrastructure.Migrations
                         .IsRequired()
                         .HasColumnType("nvarchar(450)");
 
+                    b.Property<string>("Source")
+                        .HasColumnType("nvarchar(max)");
+
                     b.Property<decimal?>("SpecificGravity")
                         .HasColumnType("decimal(18,2)");
 
@@ -7210,7 +7234,7 @@ namespace PowderCoating.Infrastructure.Migrations
                         {
                             Id = 1,
                             CompanyId = 0,
-                            CreatedAt = new DateTime(2026, 6, 14, 1, 21, 46, 131, DateTimeKind.Utc).AddTicks(4191),
+                            CreatedAt = new DateTime(2026, 6, 17, 14, 21, 27, 126, DateTimeKind.Utc).AddTicks(6644),
                             Description = "Standard pricing for regular customers",
                             DiscountPercent = 0m,
                             IsActive = true,
@@ -7221,7 +7245,7 @@ namespace PowderCoating.Infrastructure.Migrations
                         {
                             Id = 2,
                             CompanyId = 0,
-                            CreatedAt = new DateTime(2026, 6, 14, 1, 21, 46, 131, DateTimeKind.Utc).AddTicks(4196),
+                            CreatedAt = new DateTime(2026, 6, 17, 14, 21, 27, 126, DateTimeKind.Utc).AddTicks(6651),
                             Description = "5% discount for preferred customers",
                             DiscountPercent = 5m,
                             IsActive = true,
@@ -7232,7 +7256,7 @@ namespace PowderCoating.Infrastructure.Migrations
                         {
                             Id = 3,
                             CompanyId = 0,
-                            CreatedAt = new DateTime(2026, 6, 14, 1, 21, 46, 131, DateTimeKind.Utc).AddTicks(4197),
+                            CreatedAt = new DateTime(2026, 6, 17, 14, 21, 27, 126, DateTimeKind.Utc).AddTicks(6652),
                             Description = "10% discount for premium customers",
                             DiscountPercent = 10m,
                             IsActive = true,