subscribeVideos called pool.sub(getHealthyRelays(this.relays)) with no
empty-relay fallback, unlike the fetch paths in the same file. On a cold first
load the 5s relay connect probe can time out, marking every relay unreachable;
init() only warns and schedules a background reconnect (it does not throw), so
boot proceeds and the feed subscribes to ZERO relays. The background reconnect
later succeeds but nothing re-issues the subscription, so the feed stays empty
until the user refreshes (when the SWR cache renders) — the reported
"notes don't load on first visit / need a refresh" symptom.
Fall back to DEFAULT_RELAY_URLS when no relays are healthy, mirroring the
established pattern. Because the fallback bypasses the unreachable cooldown, the
subscription retries those relays directly and self-heals instead of staying
dead until refresh.
Adds tests/nostr/subscribeVideosRelayFallback.test.mjs: empty healthy set =>
default relays (never zero), populated healthy set => uses those relays.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
