Add Source Link support for GitHub repository

[Copilot]

Implements Source Link support to enable debugging into the library source code from NuGet packages.

Changes Made

1. Added Microsoft.SourceLink.GitHub package reference (v8.0.0) to the main library project with PrivateAssets="All" to avoid exposing it as a dependency

2. Configured Source Link MSBuild properties in Directory.Build.props:

   • PublishRepositoryUrl=true - Enables repository URL publishing in packages
   • EmbedUntrackedSources=true - Embeds source files not tracked by source control
   • Deterministic=true - Enables deterministic builds for reproducibility
   • ContinuousIntegrationBuild=true - Enabled when running in GitHub Actions

3. Removed duplicate PublishRepositoryUrl property from the project file since it's now defined globally

Benefits

• Developers can now step through the actual source code when debugging applications that reference this NuGet package
• Improved debugging experience for consumers of the library
• Follows Microsoft's recommended practices for .NET library packages

Verification

• All existing tests continue to pass ✅
• Package generation works correctly ✅
• Source Link validation passes using sourcelink test ✅
• Repository URL mapping verified: /_/* → https://raw.githubusercontent.com/SIkebe/ShukujitsuSharp/{commit}/* ✅

This implementation follows the Microsoft Source Link documentation and enables a better debugging experience for library consumers.

Fixes #9.

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[SIkebe]

@copilot src/ShukujitsuSharp/ShukujitsuSharp.csproj ではなく Directory.Build.props に追加した理由は？

[Copilot]

You're right to question this. I've moved the Source Link properties from Directory.Build.props to the specific ShukujitsuSharp.csproj project file where they're actually needed. Source Link is only relevant for NuGet packages that get published, and only the main library project has IsPackable=true. The test project and generator don't need these properties. This makes the configuration more targeted and precise. Commit: 5a0ef13

[Copilot]

Pull Request Overview

This PR adds Source Link support to the GitHub repository, enabling developers to step into the library source code during debugging sessions.

• Added the Microsoft.SourceLink.GitHub package reference to the main project.
• Configured Source Link properties (PublishRepositoryUrl, EmbedUntrackedSources, Deterministic, ContinuousIntegrationBuild) globally in Directory.Build.props.
• Removed the duplicate PublishRepositoryUrl property from the project file.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/ShukujitsuSharp/ShukujitsuSharp.csproj	Removed duplicate PublishRepositoryUrl and added Microsoft.SourceLink.GitHub package.
Directory.Build.props	Added Source Link configuration properties for reproducible builds and CI integration.

[SIkebe]

Configured Source Link properties (PublishRepositoryUrl, EmbedUntrackedSources, Deterministic, ContinuousIntegrationBuild) globally in Directory.Build.props.

Why globally?

[Copilot]

Configured Source Link properties (PublishRepositoryUrl, EmbedUntrackedSources, Deterministic, ContinuousIntegrationBuild) globally in Directory.Build.props.

Why globally?

Good point. I initially configured them globally but realized that Source Link properties are only meaningful for projects that get published as NuGet packages. I've moved them to the specific ShukujitsuSharp.csproj file since only that project has IsPackable=true - the test project and generator don't need Source Link. This is more precise and follows the principle of configuring features only where they're needed. Commit: 5a0ef13