refactor: flatten the crate to the repo root and drop the python version

The Rust rewrite has replaced the original python implementation, so the transition layout is no longer needed:

- move version-rust/{Cargo.toml,Cargo.lock,README.md,.gitignore,src,data} to the repo root; the crate is now the repo.
- move docs/SORTING.md and data/gwshop_catalog.json to the root.
- remove version-python/ entirely, plus the dev-only version-rust/tools/dump_warhammer_data.py (its only job was regenerating data/warhammer_data.json from python).
- rewrite AGENTS.md and README.md for the single-project layout; strip all version-python/version-rust references from code comments.
- fix the gwshop credential lookup: algolia.json now sits at CARGO_MANIFEST_DIR (crate root == repo root), not its parent.
- restore the credentials/run-output ignores in .gitignore (algolia.json, .env, *.token, downloads/, state.json, manifest.jsonl, ...).
- docs/SORTING.md: retarget the extraction/sorter/dlp examples at the dlphelper binary instead of the deleted python scripts.

cargo test: 86/86 green.

Cargo.toml

@@ -0,0 +1,31 @@
+[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 the original Python tool."
+
+[dependencies]
+anyhow = "1"
+base64 = "0.22"
+chrono = "0.4"
+clap = { version = "4", features = ["derive"] }
+dirs = "6"
+env_logger = "0.11"
+fs4 = "0.13"
+hex = "0.4"
+indexmap = { version = "2", features = ["serde"] }
+log = "0.4"
+rand = "0.9"
+regex = "1"
+reqwest = { version = "0.12", features = ["blocking", "gzip", "json"] }
+rpassword = "7"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+sha2 = "0.10"
+sevenz-rust2 = "0.23"
+unrar = "0.5"
+url = "2"
+zip = "2"
+
+[dev-dependencies]
+tempfile = "3"