Bounded optional relay display name for the host-settings footer. One
unauthenticated NIP-11 document read per configured relay URL (4 s timeout,
32 KiB cap, no redirects, cancellable) supplies a terminal-sanitized name
shown before the exact configured URL and actual connection state. Missing,
failed, oversized or control-bearing names keep the truthful URL-only
footer; the name never changes reported connection state, blocks startup,
resets configuration, carries credentials or invents a name. A relay switch
aborts the in-flight read and a late completion is never applied to a new
relay. Installed smoke loader stubs the new HTTP path; no live relay is
contacted in tests.
Signed-off-by: Logan Johnson <loganj@squareup.com>
