Create crates/alknet-tty-local with Cargo.toml (alknet-tty workspace dep, portable-pty, libc unix-only, tokio, bytes, futures-core, tracing, thiserror), src/lib.rs with module declarations and LocalTtyBackend re-export, and skeleton module files (pty, pipe, backend) with doc comments and TODO markers. Add the crate to the workspace members list.