docs(runtime): record DirectStorage WSL disposition

[alphastorm]

Disposition

The SF DirectStorage patch is non-applicable to the current NYC WSL runtime; this draft persists the architectural finding only.

• The patch targets deleted DiskStateCache and snapshot_turn_checkpoint_to_disk interfaces.
• Current persistence ownership is the StateImage / packed logical-order Host KV architecture.
• The legacy path is guarded by _WIN32 and depends on dstorage.h, D3D12/DXGI, Win32 shared handles, and CUDA-D3D12 external-memory/semaphore interop.
• The NYC sm_120a runtime is a Linux binary under WSL, so the Microsoft DirectStorage route is not a viable port target.

Verification

• Commit pushed: c155bc886ac24fec583e680efb8d88ba23e583db
• Separate worktree: /Users/srs/Development/ninfer-directstorage-nyc
• Live evaluation worktree unchanged: 35 pre-existing status entries before and after; zero added or removed paths.

Runtime status

UNVERIFIED on RTX 5090 / WSL. No sm_120a build, cache test, DirectStorage call, or GPU exercise was performed for this docs-only branch.

Merge status

BLOCKED — draft; do not merge.

• A supported NYC persistence backend and product scope are selected.
• Any future implementation is designed against StateImage and packed Host KV ownership.
• RTX 5090 / WSL runtime behavior is qualified before implementation merge.