Post AzDO build summary to PR comments

[simonrozsival]

Summary

• add a PR pipeline stage that posts an Azure DevOps timeline-based build summary to the GitHub PR conversation
• add conservative @copilot mention handling for Copilot-authored or opted-in contributor PRs
• intentionally add a failing test so this draft PR can validate the summary/comment flow

Validation

• pwsh parser check for Post-BuildSummaryComment.ps1
• dry-run script validation for actionable, infra, success, and disable-mentions cases
• YAML parse checks for azure-pipelines.yaml and variables.yaml
• targeted test run confirms BuildSummarySmokeTest_IntentionallyFails fails with the expected message

Notes

This PR is intentionally red. The failing test should be removed before this becomes ready for review/merge.

[vs-mobiletools-engineering-service2]

Azure DevOps build summary

Result: In progress

This build is still running. This comment is the latest status and will be updated when the final build-summary stage runs.

Item	Value
Build	11.0.0-preview.4.26230.1+pr.11251.azdo.13980477
Build ID	13980477
Pull request	#11251
Commit	1442613fab4b
Author	@simonrozsival

Stages

Stage	Result	Errors	Warnings
Mac	✅ succeeded	0	0
Windows	❌ failed	0	0
Linux	✅ succeeded	0	0
Package Tests	✅ succeeded	0	0
Linux Tests	✅ succeeded	0	0
MSBuild Tests	✅ succeeded	0	0
MSBuild Emulator Tests	✅ succeeded	0	0
MAUI Tests	✅ succeeded	0	0
Prepare .NET Release	➡️ skipped	0	0
PoliCheck	✅ succeeded	0	0
🔒 SDLSources	✅ succeeded	0	0

Jobs needing attention

• ❌ Windows > Build & Smoke Test - failed, 0 error(s), 0 warning(s)

Tasks needing attention

• ⚠️ Test Microsoft.Android.Sdk.TrimmableTypeMap.Tests Release - succeededWithIssues, 1 error(s), 0 warning(s)
  • error PowerShell exited with code '1'.
• ❌ Ensure no modified/untracked files - failed, 1 error(s), 0 warning(s)
  • error git tree has modified or untracked files.

Failed tests

• Microsoft.Android.Sdk.TrimmableTypeMap.Tests.AcwMapWriterTests.BuildSummarySmokeTest_IntentionallyFails - Intentional failure to verify Azure DevOps build summary PR comment posting.

Generated from Azure DevOps timeline data for build 13980477. See the linked build for full logs and artifacts.