[Task] Coordinate Foundry provider handoff release

[huimiu]

Goal

Complete the coordinated release for the Foundry provisioning ownership handoff in PR #9133.

Scope

• Publish azure.ai.projects version 1.0.0-beta.3 with ownership of the microsoft.foundry provisioning provider.
• Publish azure.ai.agents version 1.0.0-beta.6 without the provider registration.
• Update both extension entries in the registry atomically.
• Update the microsoft.foundry meta-package constraints to require the compatible pair.
• Verify installation and startup with both extensions together.

Acceptance criteria

• Both signed extension artifacts are available before registry changes merge.
• A fresh installation resolves the compatible projects and agents versions.
• No duplicate microsoft.foundry provider registration occurs.
• Existing split and pre-split Foundry projects can provision, deploy, and tear down successfully.
• Release notes state that the pair must be upgraded together during this transition.

Context

The implementation and coordinated version metadata are included in PR #9133. Registry and artifact publication must follow the release process rather than being performed in the implementation PR.