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/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "dlphelper"
+version = "0.1.0"
+edition = "2024"
+description = "Torrent-first platform for Warhammer proxy models: Discord channel export, link extraction, per-host downloaders, manifest — Rust rewrite of version-python."
+
+[dependencies]