Shared Chio substrate types extracted from chio-core.

This crate holds the protocol-wide types that should remain stable while heavier domain crates split away from the compatibility facade.

no_std support

The crate is no_std + alloc by source: under --no-default-features every module compiles against core and alloc only. This is the foundation that lets chio-kernel-core cross-compile to wasm32-unknown-unknown and other embedded targets. The default std feature re-enables std-backed error impls via thiserror, along with the std feature on every transitive dependency.