merge(furniture-domain): integrate domain decision baseline

.gitignore

@@ -1,2 +1,8 @@
 .tasks/
 .agile/
+bin/
+obj/
+TestResults/
+.vs/
+*.user
+*.suo

Furniture.Domain.slnx

@@ -0,0 +1,8 @@
+<Solution>
+  <Folder Name="/src/">
+    <Project Path="src/Furniture.Domain/Furniture.Domain.csproj" />
+  </Folder>
+  <Folder Name="/tests/">
+    <Project Path="tests/Furniture.Domain.UnitTests/Furniture.Domain.UnitTests.csproj" />
+  </Folder>
+</Solution>

docs/migration/behavior-invariants.md

@@ -4,6 +4,8 @@
 - Availability decision outcome remains unchanged for equivalent inputs.
 - Correlation propagation behavior remains unchanged.
 - Transport contracts stay stable at service boundary.
+- Missing display names map to `Unknown Furniture`.
+- Negative inventory quantities are clamped to `0`.
 
 ## Validation Approach
 - Compare pre/post extraction contract examples.

src/Furniture.Domain/Contracts/FurnitureAvailabilityDecisionRequest.cs

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+namespace Furniture.Domain.Contracts;
+
+/// <summary>
+/// Domain input for furniture availability decisions.
+/// </summary>
+/// <param name="FurnitureId">Furniture identifier.</param>
+/// <param name="CorrelationId">Correlation identifier.</param>
+public sealed record FurnitureAvailabilityDecisionRequest(string FurnitureId, string CorrelationId);

src/Furniture.Domain/Contracts/FurnitureAvailabilityDecisionResponse.cs

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+namespace Furniture.Domain.Contracts;
+
+/// <summary>
+/// Domain output for furniture availability decisions.
+/// </summary>
+/// <param name="FurnitureId">Furniture identifier.</param>
+/// <param name="DisplayName">Furniture display name.</param>
+/// <param name="QuantityAvailable">Quantity available.</param>
+public sealed record FurnitureAvailabilityDecisionResponse(
+    string FurnitureId,
+    string DisplayName,
+    int QuantityAvailable);

src/Furniture.Domain/Conventions/FurnitureDomainPackageContract.cs

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+namespace Furniture.Domain.Conventions;
+
+/// <summary>
+/// Marker type for furniture-domain package discovery.
+/// </summary>
+public sealed class FurnitureDomainPackageContract
+{
+}

src/Furniture.Domain/Decisions/FurnitureAvailabilityDecisionService.cs

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+using BuildingBlock.Catalog.Contracts.Conventions;
+using BuildingBlock.Catalog.Contracts.Products;
+using BuildingBlock.Catalog.Contracts.Responses;
+using BuildingBlock.Inventory.Contracts.Conventions;
+using BuildingBlock.Inventory.Contracts.Requests;
+using BuildingBlock.Inventory.Contracts.Responses;
+using Furniture.Domain.Contracts;
+
+namespace Furniture.Domain.Decisions;
+
+/// <summary>
+/// Default domain implementation for furniture availability composition decisions.
+/// </summary>
+public sealed class FurnitureAvailabilityDecisionService : IFurnitureAvailabilityDecisionService
+{
+    private const string ContractVersion = "1.0.0";
+
+    /// <inheritdoc />
+    public InventoryItemLookupRequest BuildInventoryRequest(FurnitureAvailabilityDecisionRequest request)
+    {
+        return new InventoryItemLookupRequest(
+            new InventoryContractEnvelope(ContractVersion, ResolveCorrelationId(request.CorrelationId)),
+            request.FurnitureId);
+    }
+
+    /// <inheritdoc />
+    public ProductContract BuildCatalogRequest(FurnitureAvailabilityDecisionRequest request)
+    {
+        return new ProductContract(
+            new CatalogContractEnvelope(ContractVersion, ResolveCorrelationId(request.CorrelationId)),
+            request.FurnitureId,
+            string.Empty);
+    }
+
+    /// <inheritdoc />
+    public FurnitureAvailabilityDecisionResponse ComposeResponse(
+        FurnitureAvailabilityDecisionRequest request,
+        ProductContractResponse catalogResponse,
+        InventoryItemLookupResponse inventoryResponse)
+    {
+        var displayName = string.IsNullOrWhiteSpace(catalogResponse.DisplayName)
+            ? "Unknown Furniture"
+            : catalogResponse.DisplayName;
+        var quantityAvailable = inventoryResponse.QuantityAvailable < 0
+            ? 0
+            : inventoryResponse.QuantityAvailable;
+
+        return new FurnitureAvailabilityDecisionResponse(
+            request.FurnitureId,
+            displayName,
+            quantityAvailable);
+    }
+
+    private static string ResolveCorrelationId(string correlationId)
+    {
+        if (!string.IsNullOrWhiteSpace(correlationId))
+        {
+            return correlationId;
+        }
+
+        return $"corr-{Guid.NewGuid():N}";
+    }
+}

src/Furniture.Domain/Decisions/IFurnitureAvailabilityDecisionService.cs

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+using BuildingBlock.Catalog.Contracts.Products;
+using BuildingBlock.Catalog.Contracts.Responses;
+using BuildingBlock.Inventory.Contracts.Requests;
+using BuildingBlock.Inventory.Contracts.Responses;
+using Furniture.Domain.Contracts;
+
+namespace Furniture.Domain.Decisions;
+
+/// <summary>
+/// Defines domain decision boundary for furniture availability composition.
+/// </summary>
+public interface IFurnitureAvailabilityDecisionService
+{
+    /// <summary>
+    /// Creates inventory capability request from furniture availability input.
+    /// </summary>
+    InventoryItemLookupRequest BuildInventoryRequest(FurnitureAvailabilityDecisionRequest request);
+
+    /// <summary>
+    /// Creates catalog capability request from furniture availability input.
+    /// </summary>
+    ProductContract BuildCatalogRequest(FurnitureAvailabilityDecisionRequest request);
+
+    /// <summary>
+    /// Composes final furniture availability response from capability responses.
+    /// </summary>
+    FurnitureAvailabilityDecisionResponse ComposeResponse(
+        FurnitureAvailabilityDecisionRequest request,
+        ProductContractResponse catalogResponse,
+        InventoryItemLookupResponse inventoryResponse);
+}

src/Furniture.Domain/Furniture.Domain.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\building-block-catalog\src\BuildingBlock.Catalog.Contracts\BuildingBlock.Catalog.Contracts.csproj" />
+    <ProjectReference Include="..\..\..\building-block-inventory\src\BuildingBlock.Inventory.Contracts\BuildingBlock.Inventory.Contracts.csproj" />
+  </ItemGroup>
+</Project>

tests/Furniture.Domain.UnitTests/Furniture.Domain.UnitTests.csproj

@@ -0,0 +1,20 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" Version="6.0.4" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
+    <PackageReference Include="xunit" Version="2.9.3" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="3.1.4" />
+  </ItemGroup>
+  <ItemGroup>
+    <Using Include="Xunit" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Furniture.Domain\Furniture.Domain.csproj" />
+  </ItemGroup>
+</Project>

tests/Furniture.Domain.UnitTests/FurnitureAvailabilityDecisionServiceTests.cs

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+using BuildingBlock.Catalog.Contracts.Conventions;
+using BuildingBlock.Catalog.Contracts.Responses;
+using BuildingBlock.Inventory.Contracts.Conventions;
+using BuildingBlock.Inventory.Contracts.Responses;
+using Furniture.Domain.Contracts;
+using Furniture.Domain.Decisions;
+
+namespace Furniture.Domain.UnitTests;
+
+public class FurnitureAvailabilityDecisionServiceTests
+{
+    [Fact]
+    public void BuildCatalogRequest_WhenCalled_UsesFurnitureIdAsProductId()
+    {
+        var service = new FurnitureAvailabilityDecisionService();
+
+        var request = service.BuildCatalogRequest(new FurnitureAvailabilityDecisionRequest("FUR-001", "corr-001"));
+
+        Assert.Equal("FUR-001", request.ProductId);
+        Assert.Equal("corr-001", request.Envelope.CorrelationId);
+    }
+
+    [Fact]
+    public void BuildInventoryRequest_WhenCorrelationMissing_GeneratesCorrelation()
+    {
+        var service = new FurnitureAvailabilityDecisionService();
+
+        var request = service.BuildInventoryRequest(new FurnitureAvailabilityDecisionRequest("FUR-001", string.Empty));
+
+        Assert.Equal("FUR-001", request.ItemCode);
+        Assert.NotEmpty(request.Envelope.CorrelationId);
+    }
+
+    [Fact]
+    public void ComposeResponse_WhenCalled_UsesCatalogAndInventoryValues()
+    {
+        var service = new FurnitureAvailabilityDecisionService();
+        var request = new FurnitureAvailabilityDecisionRequest("FUR-001", "corr-001");
+        var catalog = new ProductContractResponse(
+            new CatalogContractEnvelope("1.0.0", "corr-001"),
+            "FUR-001",
+            "Chair");
+        var inventory = new InventoryItemLookupResponse(
+            new InventoryContractEnvelope("1.0.0", "corr-001"),
+            "FUR-001",
+            12);
+
+        var response = service.ComposeResponse(request, catalog, inventory);
+
+        Assert.Equal("FUR-001", response.FurnitureId);
+        Assert.Equal("Chair", response.DisplayName);
+        Assert.Equal(12, response.QuantityAvailable);
+    }
+
+    [Fact]
+    public void ComposeResponse_WhenCatalogDisplayNameMissing_UsesFallbackName()
+    {
+        var service = new FurnitureAvailabilityDecisionService();
+        var request = new FurnitureAvailabilityDecisionRequest("FUR-004", "corr-004");
+        var catalog = new ProductContractResponse(
+            new CatalogContractEnvelope("1.0.0", "corr-004"),
+            "FUR-004",
+            string.Empty);
+        var inventory = new InventoryItemLookupResponse(
+            new InventoryContractEnvelope("1.0.0", "corr-004"),
+            "FUR-004",
+            5);
+
+        var response = service.ComposeResponse(request, catalog, inventory);
+
+        Assert.Equal("Unknown Furniture", response.DisplayName);
+    }
+
+    [Fact]
+    public void ComposeResponse_WhenInventoryNegative_ClampsQuantityToZero()
+    {
+        var service = new FurnitureAvailabilityDecisionService();
+        var request = new FurnitureAvailabilityDecisionRequest("FUR-005", "corr-005");
+        var catalog = new ProductContractResponse(
+            new CatalogContractEnvelope("1.0.0", "corr-005"),
+            "FUR-005",
+            "Shelf");
+        var inventory = new InventoryItemLookupResponse(
+            new InventoryContractEnvelope("1.0.0", "corr-005"),
+            "FUR-005",
+            -3);
+
+        var response = service.ComposeResponse(request, catalog, inventory);
+
+        Assert.Equal(0, response.QuantityAvailable);
+    }
+}