Replace Inputs/Outputs with stamp existence check for incremental builds

[MattKotsenas]

Description

Follow-up to #169 (should be merged first or taken together).

.NET SDK 10.0.102 intentionally changed where dotnet new tool-manifest places the manifest file, from .config/dotnet-tools.json to the current directory (dotnet/sdk#49296). The SDK's manifest
discovery walks up the directory tree checking both dotnet-tools.json and .config/dotnet-tools.json at each level, so manifests can now live anywhere along the path to root.

The MSBuild target's Inputs attribute had a hardcoded path to .config/dotnet-tools.json. On repos created with SDK 10.0.102+, this file doesn't exist, so MSBuild can't do the timestamp comparison, and the target re-runs every build, defeating the incremental optimization.

Rather than adding manifest discovery logic to MSBuild XML, this replaces the Inputs/Outputs mechanism with a simpler !Exists(stamp) condition. The target runs once (creating the stamp), then skips on all subsequent builds. dotnet clean
removes the stamp (via FileWrites), so the next build re-installs. If you update tool versions in the manifest, run dotnet clean or dotnet tool install to pick up the change.

Alternatively, we could create another ItemGroup or Target that searches for the dotnet-tools.json file before calling our Husky target. If we want the most deterministic build possible, I'm happy to make that change instead. However, in that case I'd suggest dropping the manual install instructions and pushing everyone more forcefully towards the attach command as part of the same change.

Depends on #169.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• I have performed a self-review of my code
• I have added tests that prove my fix is effective or that my feature works
• I have made corresponding changes to the documentation
• I have commented my code, particularly in hard-to-understand areas
• New and existing unit tests pass locally with my changes
• I did test corresponding changes on Windows
• I did test corresponding changes on Linux
• I did test corresponding changes on Mac

[Copilot]

Pull request overview

Updates Husky’s MSBuild incremental-install behavior to avoid relying on the .config/dotnet-tools.json path (which changed in .NET SDK 10.0.102), switching to a stamp-file existence check so the restore/install target can reliably skip after first run.

Changes:

• Replace MSBuild Inputs/Outputs incremental build logic with !Exists(install.stamp) gating.
• Introduce/configure a HuskyRoot MSBuild property to derive all paths (stamp, working directory) consistently.
• Update attach command generation, tests, and docs to match the new stamp + HuskyRoot approach.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tests/HuskyTest/Cli/AttachCommandTests.cs	Updates assertions to validate HuskyRoot + !Exists(stamp) condition and remove Inputs/Outputs expectations.
src/Husky/Husky.csproj	Adds HuskyRoot property and switches target gating from Inputs/Outputs to stamp existence.
src/Husky/Cli/AttachCommand.cs	Generates HuskyRoot PropertyGroup and a stamp existence condition; removes prior incremental Inputs/Outputs behavior.
docs/guide/submodules.md	Updates manual XML example to include HuskyRoot and stamp existence gating.
docs/guide/automate.md	Updates manual attach instructions and rationale to the new HuskyRoot + stamp approach.

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[MattKotsenas]

Ok, let me release this branch, then it'll be ready for review.

Edit: Updated now. @alirezanet, do you mind taking a look whenever you have time? If you have any questions, please let me know. Thanks!

[MattKotsenas]

Hi @alirezanet, sorry for the bother, but I wanted to make sure you saw this is now updated and ready for review. If you have any questions, please let me know. Thanks!

[alirezanet]

Hey @MattKotsenas,
I saw your update, but I’m a bit busy these days and can’t test it right now. If you’re confident there are no breaking changes and it’s been properly tested, I’m happy to trust you and merge it.