Files
Kyaw Thant 24550a45e3 Onboard WinAppSDK mono-build Integration (#12090)
## Summary

Onboards WinUI into the WinAppSDK mono-build by merging
`release/dev/monobuild` into `main`.
Build and pipeline infrastructure only — no product code or public API
changes.

## What changed

- **Mono-build entry point** — adds `build/WinUI-MonoBuild-Test.yml`,
plus
`WinUI-BuildTestInfra-Steps.yml` and
`WinUI-CreateDebuggerExts-Stage.yml`.

- **Dual-context templates** — new `*-Wrapper.yml` templates (ESRP
signing, symbol publish,
API-change check) dispatch to `@self` when built inside the monorepo and
to `@WinAppSDK`
when built standalone. This removes WinUI's dependency on the legacy
`WindowsAppSDKConfig` repo.

- **Maestro removed** — deletes `eng/Version.Details.xml` and the
`Microsoft.WinAppSDK.EngCommon`
MSBuild SDK. Component versions now come from the monorepo's
`WindowsAppSDK.PackageVersion.props`
when a mono-build checkout stages it above the repo; otherwise
`eng/Versions.props` falls back to
literals carried over byte-identical from the deleted file. OSS pins are
unchanged.

- **Standalone version constants** — adds `WinUI-Versions.yml`,
replacing
  `WindowsAppSDK-Versions.yml@WindowsAppSDKVersionConfig`.

- **Throughput** — `/m` parallelism across two solutions in BuildMUX;
raised WinUI test
  job/task timeouts from 100/90 to 300 minutes.


## PR Type

- [ ] Bugfix
- [ ] Feature
- [ ] Code style update (formatting, renaming)
- [x] Refactoring (no functional changes, no API changes)
- [x] Build related changes
- [ ] Documentation content changes
- [ ] Other (please describe):

## Regression Potential

- [x] Low risk — isolated change, limited scope
- [ ] Medium risk — touches shared components or public APIs
- [ ] High risk — architectural or breaking API change

## How Has This Been Tested?

- [x] I have performed a self-review of my own code
- [ ] I have added tests to cover my changes
- [ ] Existing tests pass locally
2026-09-30 15:54:05 -07:00
..