Upgrade NuGet packages and .NET tools, add AI agent documentation

.claude/settings.local.json

@@ -0,0 +1,18 @@
+{
+  "permissions": {
+    "allow": [
+      "Edit",
+      "Bash(git checkout:*)",
+      "Bash(git add:*)",
+      "Bash(git commit:*)",
+      "Bash(dotnet list:*)",
+      "Bash(dotnet build:*)",
+      "Bash(dotnet test:*)",
+      "Bash(dotnet run:*)",
+      "Bash(dotnet test)",
+      "Bash(dotnet outdated)",
+      "Bash(dotnet sdk check:*)",
+      "Bash(curl:*)"
+    ]
+  }
+}

.config/dotnet-tools.json

@@ -3,7 +3,7 @@
   "isRoot": true,
   "tools": {
     "nbgv": {
-      "version": "3.7.115",
+      "version": "3.9.50",
       "commands": [
         "nbgv"
       ]

AGENTS.md

@@ -0,0 +1,56 @@
+# CLAUDE.md
+
+This file provides guidance to AI agents when working with code in this repository.
+
+## Project Overview
+
+This repository contains `Treasure.Build.CentralBuildOutput`, an MSBuild project SDK that centralizes build output for .NET projects. Instead of placing `bin` and `obj` folders in each project directory, this SDK writes all build output to a common location with a tree structure mirroring the project structure.
+
+## Build Commands
+
+```shell
+# Build the SDK
+dotnet build
+
+# Run all tests
+dotnet test
+
+# Run tests for a specific framework
+dotnet test --framework net9.0
+```
+
+## Project Structure
+
+- `src/CentralBuildOutput/` - The MSBuild SDK package (uses `Microsoft.Build.NoTargets`)
+  - `Sdk/Sdk.props` - Entry point props imported by consuming projects
+  - `Sdk/Sdk.targets` - Entry point targets that conditionally imports the appropriate configuration
+  - `Sdk/ConfigureBuildOutput.targets` - Core logic for redirecting build output paths
+  - `Sdk/ConfigureBuildOutputForArtifacts.targets` - Configuration when using .NET 8+ artifacts output
+- `src/CentralBuildOutput.Tests/` - xUnit tests using `MSBuild.ProjectCreation` for in-memory MSBuild testing
+- `samples/CentralBuildOutput/` - Sample projects demonstrating SDK usage
+- `eng/` - Build infrastructure (analyzers, defaults, packaging configuration)
+
+## Key Architecture Details
+
+**SDK Entry Points**: The SDK uses standard MSBuild SDK conventions with `Sdk.props` and `Sdk.targets` files that get automatically imported when a project references the SDK.
+
+**Two Modes of Operation**:
+
+1. **Standard mode** (`ConfigureBuildOutput.targets`): Redirects `BaseIntermediateOutputPath`, `BaseOutputPath`, `OutputPath`, `PublishDir`, etc. to centralized folders prefixed with `__` (configurable via `CentralBuildOutputFolderPrefix`)
+2. **Artifacts mode** (`ConfigureBuildOutputForArtifacts.targets`): When `UseArtifactsOutput=true`, defers to .NET 8+ artifacts output but still centralizes test results
+
+**Path Calculation**: The SDK calculates `RelativeProjectPath` by determining the relative path from `CentralBuildOutputPath` (or `CentralBuildOutputRelativeToPath` if set) to the project directory, preserving the folder hierarchy in output.
+
+**This Repo's Own Build**: Uses .NET 8+ artifacts output (`UseArtifactsOutput=true`) with `ArtifactsPath` set to `__artifacts`.
+
+## Testing Approach
+
+Tests use `MSBuild.ProjectCreation` to create in-memory MSBuild projects and verify that the SDK correctly sets output path properties. The test project copies SDK files to its output directory to enable testing.
+
+## Versioning
+
+Uses Nerdbank.GitVersioning for version management.
+
+## Coding style
+
+The project adheres to styles defined in `.editorconfig`.

CLAUDE.md

@@ -0,0 +1 @@
+@AGENTS.md

Directory.Packages.props

@@ -19,18 +19,18 @@
     https://learn.microsoft.com/nuget/consume-packages/central-package-management#global-package-references
     -->
   <ItemGroup>
-    <GlobalPackageReference Include="Nerdbank.GitVersioning" Version="3.7.115" />
+    <GlobalPackageReference Include="Nerdbank.GitVersioning" Version="3.9.50" />
     <GlobalPackageReference Include="Microsoft.VisualStudioEng.MicroBuild.Core" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup>
     <PackageVersion Include="IsExternalInit" Version="1.0.3" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
-    <PackageVersion Include="MSBuild.ProjectCreation" Version="14.0.5" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
+    <PackageVersion Include="MSBuild.ProjectCreation" Version="17.0.1" />
     <PackageVersion Include="Neovolve.Logging.Xunit" Version="6.3.0" />
     <PackageVersion Include="Shouldly" Version="4.3.0" />
     <PackageVersion Include="xunit" Version="2.9.3" />
-    <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.3" />
+    <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5" />
   </ItemGroup>
 
 </Project>

global.json

@@ -5,6 +5,6 @@
     "rollForward": "latestPatch"
   },
   "msbuild-sdks": {
-    "Microsoft.Build.NoTargets": "3.7.56"
+    "Microsoft.Build.NoTargets": "3.7.134"
   }
 }