NOTIFIER_RELAY is string | undefined after the earlier guard fix.
deleteAlert and publishAlert passed it directly to publish() which
expects string[]. Add early-return guards to both functions.
Fixes the 2 new TS2322 errors introduced by the previous commit.
The web UI crashed on load when VITE_NOTIFIER_RELAY was not set
because normalizeRelayUrl(undefined) calls url.match(...) on the
undefined argument, producing:
TypeError: can't access property 'match', A is undefined
Fix: guard with a truthy check before calling normalizeRelayUrl,
and early-return from loadAlerts when NOTIFIER_RELAY is undefined.
Fixes bead mailship-4ic
