rust: point manifest at maintained fork (andersou/vfox-rust)

[andersou]

What

sources/rust.json → manifestUrl now points at andersou/vfox-rust instead of XZzYassin/vfox-rust. Nothing else changes: same short name rust, same test block.

Why

The current upstream (XZzYassin/vfox-rust) looks unmaintained:

• last commit 2025-09-22;
• 4 open PRs, oldest from 2025-12-11, none reviewed;
• 6 open issues, including two reporting that the plugin cannot install a usable Rust on macOS.

The plugin currently distributed by the registry is broken on macOS:

• PreInstall builds the tarball URL from RUNTIME.osType, which is darwin on macOS, producing rust-<ver>-aarch64-darwin.tar.gz → 404 (err:source file not found);
• even when the download is patched, rust-std stays in its own component prefix, so rustc never finds it and every compile fails with E0463: can't find crate for 'core';
• rustfmt/clippy fail to load librustc_driver.

Those fixes were offered upstream in XZzYassin/vfox-rust#9 (with XZzYassin/vfox-rust#10) and received no response, hence the fork.

Fork contents (v1.1.0)

• darwin/macos → apple-darwin target triple;
• PostInstall merges the rust-std payload into the rustc sysroot;
• DYLD_LIBRARY_PATH exposes rustc/lib on macOS so clippy/rustfmt load;
• available versions fetched dynamically from releases.rs;
• Apache 2.0, license and credit to the original author kept in the README.

Verification

• Manifest published and reachable: https://github.com/andersou/vfox-rust/releases/download/manifest/manifest.json (name: rust, version: 1.1.0).
• Ran script/update_plugin.py locally against the edited source: it downloads the manifest, matches the name, detects 1.0.0 → 1.1.0, fetches the zip and produces plugins/rust.json with sha256 e9835c98812aef54903c670a465e22f71f64136ec714b5d97b88d43a435ed9fa.
• On macOS (aarch64): vfox install rust@1.90.0 then rustc --version → rustc 1.90.0 (1159e78c4 2025-09-14) (matches the existing resultRegx), cargo 1.90.0, clippy 0.1.90, and cargo run on a fresh cargo init project prints Hello, world!.

Happy to hand the entry back to the original author at any time if they resume maintenance.

[andersou]

Heads-up: the fork is now at v1.1.1, which also merges the llvm-tools payload into the rustc sysroot — without it rust-objcopy (cargo's strip) aborts with Library not loaded: @rpath/libLLVM.dylib on macOS.

Re-ran script/update_plugin.py against this source: manifest version 1.1.1, zip sha256 3c7238ea17249bdc05d506f5d4ad053c6c558216b0d0bd21c9ff927d2d2bff24. No change needed to the diff in this PR — only sources/rust.json is touched and plugins/rust.json is regenerated by the hourly job.