Add cross-repo profile share validation — verify share config matches AVD expectations

[kristopherjturner]

Problem

The AVD and SOFS repos are separate — a user deploying AVD doesn't have to use SOFS for FSLogix profiles. They could use Azure Files, Cloud Cache direct, or any SMB-compatible storage. However, there's currently no cross-repo validation to confirm that what the profile share is configured as (in whatever storage solution) actually matches what the AVD session hosts expect.

Today this is entirely manual alignment: the user copies a share path from their storage deployment and pastes it into the AVD config. If it's wrong, FSLogix silently fails at logon.

Discussion Points

1. What can we validate? — Given that profiles could live on any SMB share (SOFS, Azure Files, NAS, Cloud Cache), what's the minimum we can check?
   • SMB connectivity from the session host network to the share
   • Share name and path format validity
   • NTFS permissions (CREATOR OWNER model present)
   • FSLogix-required SMB settings (Continuously Available? CachingMode?)
2. Where does this validation live? — In the AVD repo since it's the consumer of the profile share?
3. When does it run? — As a pre-flight check before session host deployment? Post-deployment validation?
4. Cross-repo contract — Should SOFS output a "profile share manifest" (JSON/YAML) that AVD can consume and validate against?

Acceptance Criteria

• Discuss and agree on validation approach
• Define what "profile share readiness" means (connectivity, permissions, settings)
• Implement validation script/check in AVD repo
• Document expected share configuration requirements
• If using SOFS: document which SOFS outputs to verify against AVD inputs

Affected Repos

• azurelocal-avd — validation scripts, pre-flight checks
• azurelocal-sofs-fslogix — potentially output a share manifest or validation endpoint