Rename nix-bindings-bindgen-raw to nix-bindings-util-sys

Adopt idiomatic Rust `-sys` crate naming convention, aligning with
the direction in PR #37 without adopting the full crate splitting.

nix-bindings-util-sys/src/lib.rs

@@ -0,0 +1,31 @@
+//! Raw bindings to Nix C API
+//!
+//! This crate contains automatically generated bindings from the Nix C headers.
+//! The bindings are generated by bindgen and include C-style naming conventions
+//! and documentation comments that don't always conform to Rust standards.
+//!
+//! Normally you don't have to use this crate directly.
+//! Instead use `nix-store` and `nix-expr`.
+
+// This file must only contain generated code, so that the module-level
+// #![allow(...)] attributes don't suppress warnings in hand-written code.
+// If you need to add hand-written code, use a submodule to isolate the
+// generated code. See:
+// https://github.com/nixops4/nixops4/pull/138/commits/330c3881be3d3cf3e59adebbe0ab1c0f15f6d2c9
+
+// Standard bindgen suppressions for C naming conventions
+#![allow(non_upper_case_globals)]
+#![allow(non_camel_case_types)]
+#![allow(non_snake_case)]
+// Clippy suppressions for generated C bindings
+// bindgen doesn't generate safety docs
+#![allow(clippy::missing_safety_doc)]
+// Rustdoc suppressions for generated C documentation
+// The C headers contain Doxygen-style documentation that doesn't translate
+// well to Rust's rustdoc format, causing various warnings:
+#![allow(rustdoc::broken_intra_doc_links)] // @param[in]/[out] references don't resolve
+#![allow(rustdoc::bare_urls)] // C docs may contain unescaped URLs
+#![allow(rustdoc::invalid_html_tags)] // Doxygen HTML tags like <setting>
+#![allow(rustdoc::invalid_codeblock_attributes)] // C code examples may use unsupported attributes
+
+include!(concat!(env!("OUT_DIR"), "/bindings.rs"));