Named-argument shims over std.
Each wrapper exists so Trust callers can write call sites with
name: value syntax: fs::read_to_string(path: p) instead of the
positional std::fs::read_to_string(p). The wrappers carry no logic;
they exist purely to make parameter names part of the signature for
Trust's named-args lowering pass.
This crate is #![strict]-marked as of RT-44. The build-time index
STD_SIGNATURES (in trust-lower) used to be generated by
parsing this file directly with syn, which would have broken the
moment the file used any Trust-specific syntax. The current
design generates a checked-in manifest at
crates/trust-std/std-signatures.txt via
cargo xtask gen-std-signatures (which lowers the source first, then
parses), and trust-lower/build.rs reads that manifest. CI
enforces freshness with cargo xtask gen-std-signatures --check.