perf: declare artifact cdylibs as normal dependencies

[wan9chi]

Motivation

Cargo compiles artifact dependencies declared under [build-dependencies] with the build-override profile — opt-level 0 even in release builds — and only root-manifest profile overrides can fix it, which every downstream workspace has to copy (rust-lang/cargo#16719). The preload libraries run inside every intercepted libc call and vt_client_napi backs the Node.js client, so their optimization should not depend on fragile per-workspace boilerplate. Declaring them under [dependencies] applies the normal profile everywhere automatically.

What this does

• Moves fspy_preload_unix/fspy_preload_windows/vt_client_napi from [build-dependencies] to target-scoped [dependencies]. They now build with the full release profile (opt-level=3, lto=fat, codegen-units=1, strip=symbols) and additionally gain panic = "abort", in this workspace and downstream ones, with no profile overrides.
• CARGO_CDYLIB_FILE_* is provided while the consuming crate compiles rather than to its build script, so hashing moves into a new materialized_artifact_macros::artifact! proc macro that reads and hashes the file at expansion time (same xxh3 {:x} format, so materialized filenames are unchanged).
• The macro declares its reads via proc_macro::tracked so a future proc-macro expansion cache can never serve a stale hash next to fresh bytes, and its expansion re-references the env var and file through include_bytes!(env!(…)) for dep-info tracking.
• When the env var is unset, the expansion branches on cfg(rust_analyzer): a well-typed stub under rust-analyzer, an actionable compile_error! under rustc. The cfg tokens never appear in successful builds, so no check-cfg declarations are needed.
• The macOS downloaded binaries switch to the same macro (their build script now publishes only a path via cargo:rustc-env), leaving materialized_artifact_build without consumers; the crate is removed.
• Target-scoping the preload deps stops musl and cross-OS builds from producing useless empty cdylibs. The known resolver panic on cfg-scoped artifact deps only affects [build-dependencies] placement.

Behavior note: panic = "abort" now applies to vt_client_napi — a panic in the addon aborts the Node process instead of unwinding into napi-rs's catch_unwind. This matches the workspace-wide abort policy.

🤖 Generated with Claude Code

[github-actions]

fspy benchmark

linux

dynamic/launch             change  -5.12%  [-12.17% ..  +4.35%]  overhead   +50.92%
dynamic/access             change -34.24%  [-35.47% .. -33.11%]  overhead    +6.32%
dynamic/access-relative    change -46.60%  [-47.20% .. -46.09%]  overhead   +46.51%
static/launch              change  +0.53%  [-10.51% ..  +9.73%]  overhead  +144.96%
static/access              change  +0.66%  [ -1.35% ..  +5.07%]  overhead  +813.60%
static/access-relative     change  +1.37%  [ -1.32% ..  +6.24%]  overhead +1318.01%

macos

dynamic/launch             change  -1.27%  [ -7.17% ..  +4.26%]  overhead  +238.11%
dynamic/access             change -21.96%  [-27.57% .. -12.53%]  overhead    +3.74%
dynamic/access-relative    change -12.68%  [-18.46% ..  -5.33%]  overhead  +252.16%

windows

dynamic/launch             change  -2.84%  [-13.15% ..  +5.73%]  overhead   +25.73%
dynamic/access             change  -5.27%  [-11.66% ..  -0.13%]  overhead    +2.54%
dynamic/access-relative    change  -7.28%  [-30.58% ..  +0.62%]  overhead    +1.85%