Align Cloud Cache scope — SOFS=DR only, AVD=offer as alternative profile storage

[kristopherjturner]

Problem

Cloud Cache is referenced in both repos but with overlapping and inconsistent scope:

• SOFS repo: Has a dedicated docs/architecture/cloud-cache.md covering Cloud Cache as a DR overlay for SOFS — This is correct for the SOFS repo's scope
• AVD repo: Lists cloud_cache as a FSLogix topology option in variables.example.yml and docs/guides/fslogix.md, but marks it as "in progress" — The coverage is incomplete

The Key Distinction

Cloud Cache can serve two different purposes:

1. DR overlay for SOFS — SOFS is the primary storage; Cloud Cache replicates to a secondary target (Azure Blob, another SMB share) for disaster recovery. This is the SOFS repo's use case.
2. Alternative TO SOFS — Cloud Cache can entirely replace SOFS by writing profiles directly to multiple providers (Azure Blob, Azure Files, etc.) without needing a local file server. This is a valid AVD deployment pattern that doesn't involve SOFS at all.

Current Problem

• SOFS repo should only reference Cloud Cache in the context of DR for SOFS
• AVD repo should offer Cloud Cache as one of several alternatives for profile storage, including but not limited to:
  • SOFS on Azure Local (companion repo)
  • Cloud Cache direct (no SOFS needed)
  • Azure Files (SMB share in Azure, accessed via ER/VPN)
  • Any other SMB-compatible storage that works with Azure Local

Acceptance Criteria

• Audit SOFS repo — ensure Cloud Cache references are scoped to DR only, not presented as a replacement for SOFS itself
• Audit AVD repo — ensure Cloud Cache is presented as an alternative to SOFS, not just a topology within the SOFS deployment
• AVD repo should clearly document: "You can use SOFS, Cloud Cache, Azure Files, or any SMB share for profiles"
• SOFS repo should clearly state: "Cloud Cache in this repo is for disaster recovery of SOFS data only"
• Cross-link: SOFS → AVD for "if you want Cloud Cache as primary storage, see AVD repo"; AVD → SOFS for "if you want a local HA file server"

Affected Repos

• azurelocal-sofs-fslogix — docs/architecture/cloud-cache.md, docs/configuration/fslogix.md
• azurelocal-avd — docs/guides/fslogix.md, config/variables.example.yml