Options::token_env (default none) replaces the hard-coded LIGHTCRAFT_SAM3_TOKEN, so a download of one model can
never send another model's token to its host. SAM 3 names its variable through lightcraft_segment::fetch::options().
The decision (non-empty, https, the host the download began at) is a small function with its own test.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
The downloader in lightcraft-segment (mirrors, resume, pinned SHA-256, pure-Rust
HTTPS) was already generic apart from four SAM 3 constants. Move it to
crates/fetch (L0, native only) so other model features can use it without
depending on the SAM 3 inference code. lightcraft-segment keeps SAM3_FILES,
DEFAULT_MIRRORS, MIRRORS_ENV and wraps mirrors(); no behaviour change. The
downloader's 13 tests moved with it.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
- The crate ports Apache-2.0-only Hugging Face transformers code: it is
now `license = "Apache-2.0"`, and every ported file carries the
modification notice Apache-2.0 §4(b) asks for.
- Weights::open checks every tensor's byte range (and the header)
against the file's length: a truncated or damaged download is an
error at load, never a short read later; regression test with
hostile offsets.
- fetch/: the model download, only when asked for. An ordered mirror
list (env LIGHTCRAFT_SAM3_MIRRORS, a mirrors file, DEFAULT_MIRRORS —
empty until LightCraft's CDN exists, TODO for the maintainer),
fallback to the next mirror, resume via Range, redirects, connect and
stall timeouts, cancel, size caps, exact size + SHA-256 (pinned from
tools/install-sam3.sh) before an atomic rename; damaged files are
deleted, HTTP error bodies never written.
- HTTP/1.1 client over std sockets + rustls with the RustCrypto provider
(rustls-rustcrypto) and webpki-roots: no ring / aws-lc-rs, nothing
compiled from C (no new `cc` users in the app's build graph).
- Tests against a local TcpListener server (no internet): fallback,
redirects, chunked bodies, resume, 416, hash mismatch, too much data,
stalls, cancel.
- *.safetensors are gitignored.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
