Preact + Vite standalone admin-ui bundled into the server binary via
rust-embed. Login is NIP-07 (Smirk wallet signs the NIP-98 admin
challenge); tabs cover instance status, admin keys, invite codes, and
the effective-config editor (live vs restart-required per field).
admin-ui/dist is committed because rust-embed reads it at compile time;
node_modules is gitignored (npm ci reproduces it). A lib test asserts
index.html and the /admin/ asset base are embedded so an unbuilt
console fails the build instead of an operator.
The console is served on the admin plane only (loopback bind), behind
the existing NIP-98 admin_guard + MAC allowlist.
