A standalone, self-hostable Grin light-wallet-server mirroring the Monero LWS:
register a view/rewind credential, run a background chain scanner, rewind outputs
against registered keys, store per-account matches in a DB, and serve balance /
outputs / broadcast / height fast (vs the current on-demand stateless scan proxy).
This is the scaffold — README (architecture + HTTP surface + DB schema + how a
wallet backend proxies to it), Cargo skeleton, migrations sketch, and route/scanner
stubs. Public-clean: no operator-specific infra, hosts, or secrets.
