docs: verify setup recovery

docs/SETUP.md

@@ -33,10 +33,20 @@ The verified corpus is five archives, 560 regular file occurrences, and 132 dist
 - All 560 extracted files verified against archive-member hashes; repeat unpack reports every build unchanged.
 - Nix shell enters successfully on the current Apple Silicon macOS host; environment tool versions are verified.
 - All four declared system outputs evaluate; the actual Apple Silicon `checks.aarch64-darwin.setup` derivation builds successfully with an asset-free source fileset.
-- Setup hooks, staged pointer inspection, direnv reload, post-rename verification, and the first Xet upload pass. HF metadata reports all 580 assets as Xet-backed. Cold-clone final verification is pending the empty-directory regression fix below.
+- Setup hooks, staged pointer inspection, direnv reload, and post-rename path checks pass. The initial upload succeeded, and HF tree metadata independently reports all 580 asset files as Xet-backed with LFS metadata.
 
 Linux, Intel macOS, runtime graphics, full resource dependency indexing, and asset conversion/recode tools remain future tasks. The original software license/permission investigation remains a separate open research item; this setup does not mark it resolved.
 
 ## Fresh-clone extraction correction
 
 The first hydrated-clone test found that Git omits empty original ZIP directories (for example `data/models`). The unpacker now verifies all existing file bytes before restoring missing original directories, and still refuses changed files without writing into them. A dedicated regression covers both restoration and refusal after a file edit.
+
+## Completed remote recovery check
+
+Implementation commits: `29ed697` (setup) and `81d1607` (empty-directory recovery). The user-created HF initial commit is retained.
+
+A fresh SSH clone with skip-smudge first built the code-only Nix check while reference files were still pointers. With explicitly empty LFS and Xet caches, `assets.py fetch` recovered all 580 payloads and matched every staged pointer hash. `references.py unpack` restored the original empty directories; `verify --check-extracted` then checked all 560 extracted files across all five builds. The temporary clone remained clean and was removed afterward.
+
+The installed Git Xet agent handles Xet upload integration. This client's download trace selects the standard LFS `basic` adapter/compatibility bridge; HF metadata confirms the backend objects are Xet-backed for every file, including small TXT/CFG/IXPL resources. Download transport does not turn those payloads into ordinary Git blobs.
+
+All four declared Nix system outputs evaluate. Actual shell, direnv/local overrides, setup tests (28 passing), code-only Nix derivation, and reference round trip were exercised on Apple Silicon macOS. Linux and Intel macOS execution remain unverified. No original program or plugin was executed.

docs/TODO.md

@@ -41,7 +41,7 @@ Each task ID is stable. Split tasks into child IDs as evidence grows. Record dep
 - [x] P1.16 Provide Nix commands for environment/storage checks, hydration, extraction/verification/indexing, and setup tests. Future Cargo/replay/package commands remain in P10–P16.
 - [x] P1.17 Exclude assets/caches from Nix build/check filesets and prove code checks work without hydrated assets. Git-backed flake imports can still include hydrated files; use skip-smudge for code-only CI.
 - [x] P1.18 Test routing in disposable repos: arbitrary-extension binary, text/reference assets, pointer placement, missing setup/driver, history violations, attribute overrides, symlinks, and ordinary code/test preservation.
-- [ ] P1.19 Verify a small permitted payload upload/download through Xet and hash-check it in an empty cache; do not treat configured filters alone as upload proof.
+- [x] P1.19 Verify a small permitted payload upload/download through Xet and hash-check it in an empty cache; do not treat configured filters alone as upload proof.
 - [x] P1.20 Document first-clone bootstrap, local setup, direnv trust, authentication, offline reference operation, and the single-repository code/pointer workflow.
 
 ## P2 — Preservation and extraction scripts