[yeelam-gordon]

Scope: Windows Arm64 pre-action readiness

This PR adds the native Arm64 build foundation for OpenShotAudio. It does not attempt upstream signing, publication, or release ownership.

Changes

• native CLANGARM64 GitLab lane and GitHub-hosted windows-11-arm presubmit
• fail-closed native-host and PE payload architecture validation
• exact package/version lock validation
• optional-ASIO handling (JUCE_ASIO=0 when the SDK is unavailable) while retaining WASAPI

Evidence

• hosted native Windows Arm64 build/test/install/architecture workflow passed
• validator tests pass
• existing non-Arm lanes remain intact

Dependency order

This is PR A. OpenShot/libopenshot#1089 consumes its Arm64 artifact.

Post-actions owned by maintainers

Production GitLab runner registration, signing, release publication, and official support announcement.

AI assistance disclosure: implementation and review used GitHub Copilot CLI.

[yeelam-gordon]

Automated review is being run on mirror PR yeelam-gordon#1. Findings and fixes are pushed to this same head branch. A GitHub-hosted Windows Arm64 workflow has exercised the native CLANGARM64 configure/build path; final current-head CI remains queued.

[yeelam-gordon]

Native hosted Windows Arm64 evidence: workflow https://github.com/yeelam-gordon/libopenshot-audio/actions/runs/33169651801 attempt 2 passed the complete CLANGARM64 package install, configure, compile, test, install, and architecture-validation job.

[jonoomph]

Thanks for laying the groundwork! Native ARM support is a future goal for OpenShot. Two improvements would strengthen this: make the locked package versions reliably available, and verify the actual process architecture independently. Microsoft’s example shows x64 emulation returning the same (UNKNOWN, ARM64) pair, so that result alone isn’t conclusive. Could you add coverage for that case and refresh the native build evidence?

[jonoomph]

Thank you for laying the groundwork for native Windows ARM64 builds! I've retargeted this PR to arm64-support so we can integrate the audio, library, and application changes in dependency order and verify that our existing builders still work before merging anything into develop.

We'll handle the small integration fixes here, including package-version availability and an independent check of the running executable's architecture. ARM jobs will remain optional while we validate this work. This integration merge won't constitute an official ARM64 release or support announcement.