chore: start transition layout — python into version-python/, scaffold version-rust/

- git mv of all existing files into version-python/ (history preserved)
- version-rust/: minimal cargo scaffold (edition 2024), no deps yet
- root AGENTS.md documents the transition rules and artifact/schema contract
- main is untouched; the python layout there stays as-is

version-rust/README.md

@@ -0,0 +1,36 @@
+# version-rust
+
+Rust rewrite of `version-python` (same repo, `main` branch still carries the
+flat python layout). Goal: one concise binary + webapp, eventually replacing
+the python tooling.
+
+## Why this structure
+
+- `main` stays untouched (flat python layout) until the rewrite reaches parity.
+- This branch re-homes the python code into `version-python/` (via `git mv`,
+  history preserved) and starts `version-rust/` beside it.
+- `version-python/AGENTS.md` still documents the python stage — its rules
+  (secrets, failure policy, idempotency, rate limiting) apply to the rewrite
+  too and are the contract the Rust version must keep.
+
+## Planned crate choices (initial, adjust as modules get ported)
+
+| Concern | Python today | Rust plan |
+|---|---|---|
+| 7z extraction (extract_all) | 7z CLI, cp437 name repair, /var/tmp fallback | `sevenz-rust2` (pure Rust, LZMA2/PPMD/AES-256); zip via `zip` crate; rar likely still needs an external tool |
+| HTTP client | `requests` | `reqwest` (blocking first, async where the webapp needs it) |
+| sha256 (gofile website token, --hash manifest) | hashlib | `sha2` |
+| Fuzzy matching (sorter) | difflib-style ratios | `strsim` — port thresholds exactly, add unit tests |
+| CLI | argparse | `clap` |
+| Webapp | — | `axum` (CLI parity first, webapp second) |
+| Discord export | DCE docker container (external) | unchanged: shell out to docker |
+
+## Port order (suggested)
+
+1. `state` / `globalstore` — state.json + urls.json schemas must stay
+   backward compatible with the python versions.
+2. hosters: `gofile` (one guest account per run!), `zero807` (UA + Referer).
+3. extraction + manifest appender.
+4. catalogue / sorter (hardest logic; port the matching rules documented in
+   `version-python/AGENTS.md` §7 with tests).
+5. webapp on top.