Rust Swift FFI

This skill owns the contract between a hand-written C ABI and its Swift wrapper. Keep the exported C surface small. Keep domain behavior in ordinary Rust code and idiomatic Swift types outside the boundary.

Route neighboring work to these skills when they are installed:

• uniffi-boundary when UniFFI generates the Swift API. Do not keep a second hand-written ABI for the same surface.
• rust-ios-build for Apple targets, modulemap staging, XCFramework, SwiftPM.
• rust-native-linking for build.rs and cbindgen setup.
• rust-unsafe for raw-pointer soundness, layout, and the unsafe_code policy.
• rust-sanitizers-miri for Miri and sanitizer flags.
• rust-panic-safety for the unwind audit and the panic hook.
• ffi-error-progress-cancel for a shared mobile error, progress, and cancellation model.

First decide whether a hand-written ABI is necessary