ntkd: the Netsukuku routing daemon. Composition root wiring the eleven ntk-* library
crates into a running node; see research/notes/02-vala-services-daemon.md §5 for the
upstream daemon this replaces.
A library target (with src/main.rs as a thin fn main shim over it)
exists so integration tests can use ntkd::... directly instead of re-including source
files with #[path] — the previous approach compiled kernel/node as an entirely separate
crate per test binary, which made every test-only accessor (e.g.
kernel::routes::RouteInstaller::kernel_ref) look dead to cargo clippy's per-crate
dead-code analysis when only the bin target was checked.