Delete the deprecated Leaf derive path, migrate the remaining tests and example to leaf!, and add direct coverage for endpoint-only, TUI-only, and shared-host leaf declarations.
Introduce a function-like leaf declaration macro, bind endpoint and TUI hosts to shared generated metadata, and move remote shell endpoint construction out of the leaf module into the examples and runtime assembly code.
Update the remote shell examples to use unshell::leaves and the leaf_endpoint feature-gated endpoint module, and restore the local macro aliasing needed after removing the direct unshell dependency from unshell-leaves.
Move the protocol runtime into unshell-protocol and remote shell leaf code into unshell-leaves so endpoint and TUI roles can compile independently without circular dependencies.
Michael Mikovsky