Make TensorSharp.slnx MSBuild-compatible

[zhongkaifu]

Motivation

• Fix the MSB4068 parsing error where <Solution> in TensorSharp.slnx is unrecognized by some .NET/MSBuild toolchains by making the file valid MSBuild XML.

Description

• Replace the custom <Solution> format in TensorSharp.slnx with a standard MSBuild <Project> file that includes all projects in a ProjectsToBuild item group and adds Build, Clean, Restore, and Rebuild targets that forward to each project while propagating Configuration and Platform.

Testing

• Attempted dotnet build TensorSharp.slnx -c Release could not be executed in this environment because dotnet was not installed (error: /bin/bash: dotnet: command not found).
• Inspected the updated TensorSharp.slnx contents and verified it contains the ItemGroup with project entries and the expected MSBuild targets.

---

Codex Task

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 317ec52d40

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Use SLNX schema in .slnx files

Changing the root element to <Project> makes this a traversal MSBuild project, not an SLNX solution file. On toolchains that natively support .slnx (for example .NET SDK 9.0.200+ / VS 17.14+), .slnx is parsed with the SLNX serializer and expects a <Solution> root, so solution operations (such as dotnet sln ...) and builds targeting TensorSharp.slnx can fail as an invalid solution format. Since this repo documents dotnet build TensorSharp.slnx, keeping non-SLNX XML under a .slnx extension introduces a compatibility regression.

Useful? React with 👍 / 👎.