[Amantux]

Phase 6 first increment. The review asked to test real data-plane behaviors, not only REST. The data plane is an in-process virtual FS + hydration cache (no libfuse mount yet), so the meaningful behaviors are tested at that level:

• offline read errors clearly until hydrated, then serves real bytes to dest
• eviction forces re-hydration (no stale serve)
• concurrent opens of an offline file all fail cleanly (no race/crash)
• missing file → FileNotFoundError; write/delete → PermissionError (read-only)

Scope assessment (the recurring pattern): NasFileState/VirtualFileStatus already model online/offline/hydrating/exporting/missing/corrupt — the review overstated this gap too. The genuinely-missing bits (foreign media, vault, fragmentation, small-file aggregation, sequestered) are deferred rather than added as unused enum values (no third usage yet). A containerized SMB/NFS client harness is a follow-up once the FS is wired to libfuse — there's no real mount to serve yet.

12 fuse tests green (5 new + 7 existing).

https://claude.ai/code/session_012K5Zjc2bggcyJtFbz2D4Pw

[Copilot]

Pull request overview

Adds scenario-focused unit tests for the Tape-NAS “data plane” (the in-process virtual filesystem + hydration cache) to validate hydration/offline behavior beyond REST-level checks.

Changes:

• Add unit tests that verify offline reads fail until hydrated, then succeed with correct bytes written to a destination file.
• Add tests ensuring cache eviction forces re-hydration (no reads from an evicted cache entry).
• Add concurrency/read-only/missing-file scenarios to ensure consistent errors and read-only enforcement.