Merge latest Library.Template

[Copilot]

Merges Library.Template tip 7b5f5bfa226bc7c32aed79544eb54b2838668d4d as a true merge commit (not squash/rebase).

• Template baseline

  • Updates DocFX and development container SDK configuration.
  • Adopts MTP 2.4.1 and xunit v3 MTP 4.0.1 package baselines.

• Repository-specific integration

  • Preserves the Windows release/signing workflow.
  • Updates xunit.analyzers to 2.1.0, required by xunit v3 MTP 4.0.1.

<MicrosoftTestingPlatformVersion>2.4.1</MicrosoftTestingPlatformVersion>
<XunitV3LibraryVersion>4.0.1</XunitV3LibraryVersion>
<PackageVersion Include="xunit.analyzers" Version="2.1.0" />

Original prompt

Update this repo to the current Library.Template tip via a TRUE merge commit (not squash/rebase-only).

Critical target

Library.Template tip (must be the merge SourceCommit / second parent):
7b5f5bfa226bc7c32aed79544eb54b2838668d4d
(has docfx 2.80.1, ubuntu 26, MTP 2.4.1, etc.)

This repo is behind tip (docfx still 2.78.5 in .config/dotnet-tools.json). There is NO open auto/libtemplateUpdate PR — create a new PR with title exactly: Merge latest Library.Template

You MUST run ./tools/MergeFrom-Template.ps1 so the merge commit's SourceCommit/second parent is exactly 7b5f5bfa226bc7c32aed79544eb54b2838668d4d.

Follow the update-library-template skill

Instructions mirror https://github.com/AArnott/Library.Template/blob/main/.agents/skills/update-library-template/SKILL.md and template-release-notes.md:

1. From repo root, run ./tools/MergeFrom-Template.ps1 (creates a true git merge --no-ff from Library.Template).
2. Resolve merge conflicts per policy:
   • Always keep CURRENT version of README.md (discard incoming).
   • Refer to template-release-notes.md for special notes (incoming side).
   • When incoming changes a file deleted locally, typically re-delete; but apply test project template changes (e.g. test/Library.Tests/Library.Tests.csproj) to all real test projects, then re-delete the template file.
   • Never leave Library.slnx; migrate root .sln to .slnx with dotnet solution EXISTING.sln migrate if needed; update script/doc references.
   • Some repos intentionally reject template patterns (e.g. MTPv2); if unclear whether to catch up or keep current, leave clear notes rather than guessing wrongly.
3. Validate after conflict resolution:
   • dotnet restore succeeds
   • dotnet build succeeds
   • tools/dotnet-test-cloud.ps1 succeeds
     (If azure-pipelines/dotnet.yml or .github/workflows/build.yml use msbuild.exe instead of dotnet CLI, validate with that tool.)
4. You are not responsible for unrelated pre-existing failures; if validation fails for reasons unrelated to the merge, document that clearly.
5. Committing:
   • Preserve the merge commit (do not squash the template merge).
   • Conflict-resolution fixes ideally amended into the merge commit; novel fixes for SDK/dependency breaks go in SEPARATE commits after the merge.
   • Author commits as: git commit --author "🤖 Copilot <no-reply@github.com>"
   • Describe conflict resolutions in the commit message.

PR requirements

• Title must be exactly: Merge latest Library.Template
• Body should note this is a merge (not squash) and that SourceCommit is 7b5f5bfa226bc7c32aed79544eb54b2838668d4d.
• After done, leave the PR ready for MERGE-method auto-merge (not squash).

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.07%. Comparing base (1150656) to head (01fde3e).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #232   +/-   ##
=======================================
  Coverage   82.07%   82.07%           
=======================================
  Files          48       48           
  Lines         993      993           
  Branches       95       95           
=======================================
  Hits          815      815           
  Misses        146      146           
  Partials       32       32           

Flag	Coverage Δ
Linux	80.63% <ø> (ø)
Windows	81.87% <ø> (ø)
macOS	80.63% <ø> (ø)

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