chore(repo): keep squad artifacts out of git

[indierawk2k2]

Summary

• remove the tracked .squad files currently present on master
• remove stale test comments that linked to deleted .squad handoff documents
• keep .squad/ ignored with an explicit local-state comment
• add a repo hygiene CI job that fails when any root .squad path is tracked
• make the existing test check fail if repo hygiene fails, so existing branch protection still blocks leaks
• gate tag releases on repo hygiene, test, build, and extension build success while preserving optional MSIX behavior

Validation

• git diff --check
• git ls-files .squad returned 0 tracked paths after cleanup
• git ls-files contains no tracked filenames with squad/.squad
• git grep --cached -n -i squad -- . returns only the intentional CI guard and .gitignore entries
• ./build.ps1
• dotnet test ./tests/OpenClaw.Shared.Tests/OpenClaw.Shared.Tests.csproj --no-restore
• dotnet test ./tests/OpenClaw.Tray.Tests/OpenClaw.Tray.Tests.csproj --no-restore

Review notes

• Reviewed adversarially with GPT-5.5 rubber-duck passes; updated the CI guard so it fails the existing test check, prevents tag release jobs from proceeding after hygiene/test/build failures, and removes stale tracked comments that pointed at deleted .squad handoff files.