feat(rust): port state.py, globalstore.py and manifest appending

- src/state.rs: per-run state.json (status/attempts/error/files/updated),
  corrupt-file -> *.json.bak restart, atomic tmp+rename save, mark() parity
  (attempts increments, None fields never clear existing values)
- src/globalstore.rs: cross-run urls.json at XDG_DATA_HOME or
  ~/.local/share/dlphelper/urls.json, disabled-store no-op
- src/manifest.rs: append_manifest as compact JSONL, UTF-8
- unknown/extra JSON fields are preserved on round-trip so both versions can
  read each other's artifacts (schema contract per AGENTS.md)
- 14 unit tests

version-rust/Cargo.toml

@@ -5,3 +5,13 @@ 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]
+anyhow = "1"
+chrono = "0.4"
+dirs = "6"
+env_logger = "0.11"
+log = "0.4"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+
+[dev-dependencies]
+tempfile = "3"