Optional private build sandbox repo (user choice)

[Al-Qassim]

Context

Cloud builds currently ensure a public GitHub sandbox repo (asl-builds-android-studio-lite) so Actions can run without consuming private-minute quota.

What to build

Let the user choose public vs private for the build sandbox (Settings and/or Preparing), and update ensureSandbox accordingly.

Acceptance criteria

• User can select public (default) or private for the ASL build sandbox
• Changing visibility is applied on next ensure/upgrade (or clearly explained)
• Private choice is honest about Actions minutes / limits
• Out of scope: migrating an existing public sandbox’s history; second provider

Notes

Deferred from #25 / real cloud-build work — ship public-only first.

[Al-Qassim]

Backlog — deferred from #25. Shipping public sandbox first.

[Al-Qassim]

Tracked while shipping public-only sandbox in #28

[webbrain-one]

Hey! 👋

I've opened PR #50 to address this. It fixes the sandbox logic to let users choose between a public or private build sandbox repo, updating ensureSandbox to respect that choice.

Let me know if you have any feedback!