Add and use relay list settings

app/utils/nostr.js

@@ -0,0 +1,15 @@
+export function normalizeRelayUrl(url) {
+  if (!url) return '';
+  let normalized = url.trim().toLowerCase();
+  if (!normalized) return '';
+
+  if (!normalized.startsWith('ws://') && !normalized.startsWith('wss://')) {
+    normalized = 'wss://' + normalized;
+  }
+
+  while (normalized.endsWith('/')) {
+    normalized = normalized.slice(0, -1);
+  }
+
+  return normalized;
+}