Fix pricing consistency across Quote → Job → Invoice; add stage-flow tests

- Store complete PricingBreakdownJson snapshot on Job at every save point so
  the Details page reads stored data rather than re-running the pricing engine
- Add 7 missing fields to Quote entity (FacilityOverheadCost, tier/quote discounts,
  SubtotalAfterDiscount) and persist them via ApplyPricingSnapshot
- Fix OvenCostId-as-rate bug in JobsController (FK was passed as decimal $/hr)
- Fix hardcoded LaborCost * 0.4 multiplier in two JobItemAssemblyService overloads
- Fix FacilityOverheadCost dropped from invoices in both quote and direct-job paths
- Fix RushFee missing from direct-job invoices (read from PricingBreakdownJson)
- Fix Notes and CatalogItemId not copied to InvoiceItem
- Add 14 unit tests in PricingStageFlowTests covering all three pricing stages

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

src/PowderCoating.Infrastructure/Migrations/20260515162936_AddJobPricingSnapshot.cs

@@ -0,0 +1,71 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace PowderCoating.Infrastructure.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddJobPricingSnapshot : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "PricingBreakdownJson",
+                table: "Jobs",
+                type: "nvarchar(max)",
+                nullable: true);
+
+            migrationBuilder.UpdateData(
+                table: "PricingTiers",
+                keyColumn: "Id",
+                keyValue: 1,
+                column: "CreatedAt",
+                value: new DateTime(2026, 5, 15, 16, 29, 32, 589, DateTimeKind.Utc).AddTicks(4618));
+
+            migrationBuilder.UpdateData(
+                table: "PricingTiers",
+                keyColumn: "Id",
+                keyValue: 2,
+                column: "CreatedAt",
+                value: new DateTime(2026, 5, 15, 16, 29, 32, 589, DateTimeKind.Utc).AddTicks(4623));
+
+            migrationBuilder.UpdateData(
+                table: "PricingTiers",
+                keyColumn: "Id",
+                keyValue: 3,
+                column: "CreatedAt",
+                value: new DateTime(2026, 5, 15, 16, 29, 32, 589, DateTimeKind.Utc).AddTicks(4625));
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "PricingBreakdownJson",
+                table: "Jobs");
+
+            migrationBuilder.UpdateData(
+                table: "PricingTiers",
+                keyColumn: "Id",
+                keyValue: 1,
+                column: "CreatedAt",
+                value: new DateTime(2026, 5, 15, 0, 30, 26, 273, DateTimeKind.Utc).AddTicks(2464));
+
+            migrationBuilder.UpdateData(
+                table: "PricingTiers",
+                keyColumn: "Id",
+                keyValue: 2,
+                column: "CreatedAt",
+                value: new DateTime(2026, 5, 15, 0, 30, 26, 273, DateTimeKind.Utc).AddTicks(2473));
+
+            migrationBuilder.UpdateData(
+                table: "PricingTiers",
+                keyColumn: "Id",
+                keyValue: 3,
+                column: "CreatedAt",
+                value: new DateTime(2026, 5, 15, 0, 30, 26, 273, DateTimeKind.Utc).AddTicks(2474));
+        }
+    }
+}

src/PowderCoating.Infrastructure/Migrations/ApplicationDbContextModelSnapshot.cs

@@ -4217,6 +4217,9 @@ namespace PowderCoating.Infrastructure.Migrations
                     b.Property<int?>("OvenCycleMinutes")
                         .HasColumnType("int");
 
+                    b.Property<string>("PricingBreakdownJson")
+                        .HasColumnType("nvarchar(max)");
+
                     b.Property<int?>("QuoteId")
                         .HasColumnType("int");
 
@@ -6711,7 +6714,7 @@ namespace PowderCoating.Infrastructure.Migrations
                         {
                             Id = 1,
                             CompanyId = 0,
-                            CreatedAt = new DateTime(2026, 5, 15, 0, 30, 26, 273, DateTimeKind.Utc).AddTicks(2464),
+                            CreatedAt = new DateTime(2026, 5, 15, 16, 29, 32, 589, DateTimeKind.Utc).AddTicks(4618),
                             Description = "Standard pricing for regular customers",
                             DiscountPercent = 0m,
                             IsActive = true,
@@ -6722,7 +6725,7 @@ namespace PowderCoating.Infrastructure.Migrations
                         {
                             Id = 2,
                             CompanyId = 0,
-                            CreatedAt = new DateTime(2026, 5, 15, 0, 30, 26, 273, DateTimeKind.Utc).AddTicks(2473),
+                            CreatedAt = new DateTime(2026, 5, 15, 16, 29, 32, 589, DateTimeKind.Utc).AddTicks(4623),
                             Description = "5% discount for preferred customers",
                             DiscountPercent = 5m,
                             IsActive = true,
@@ -6733,7 +6736,7 @@ namespace PowderCoating.Infrastructure.Migrations
                         {
                             Id = 3,
                             CompanyId = 0,
-                            CreatedAt = new DateTime(2026, 5, 15, 0, 30, 26, 273, DateTimeKind.Utc).AddTicks(2474),
+                            CreatedAt = new DateTime(2026, 5, 15, 16, 29, 32, 589, DateTimeKind.Utc).AddTicks(4625),
                             Description = "10% discount for premium customers",
                             DiscountPercent = 10m,
                             IsActive = true,