fix(cordn): back off on relay pressure and surface relay health

scripts/host/relay-health.sh

@@ -47,6 +47,26 @@ disk=$(df --output=pcent / | tail -1 | tr -d ' %')
 avail=$(free -m | awk '/Mem:/{print $7}')
 [ "${avail:-0}" -lt 300 ] && ISSUES+=("low memory: ${avail} MiB available")
 
+# Cordn/Staircase RPC health. Newlay logs one warning per rejected request, so
+# a burst is easy to miss in routine log noise. Surface it as an operational
+# problem before users experience a stuck private chat.
+cordn_rejects=$(docker logs --since 15m newlay-newlay-1 2>&1 | grep -c 'cordn rate limit' || true)
+[ "${cordn_rejects:-0}" -ge 40 ] && ISSUES+=("cordn rate limits: ${cordn_rejects} rejects in 15m")
+
+if ! docker logs --since 20m newlay-newlay-1 2>&1 | grep -q 'cordn announce'; then
+  ISSUES+=("cordn coordinator has not announced in 20m")
+fi
+
+# TLS expiry (Caddy auto-renews; this catches a broken renewal early).
+expiry=$(echo | openssl s_client -servername relay.skate-spots.org -connect relay.skate-spots.org:443 2>/dev/null \
+  | openssl x509 -noout -enddate 2>/dev/null | cut -d= -f2)
+if [ -n "$expiry" ]; then
+  days=$(( ( $(date -d "$expiry" +%s) - $(date +%s) ) / 86400 ))
+  [ "$days" -lt 14 ] && ISSUES+=("relay TLS expires in ${days}d")
+else
+  ISSUES+=("could not read relay TLS certificate")
+fi
+
 sig=""
 [ "${#ISSUES[@]}" -gt 0 ] && sig=$(printf '%s\n' "${ISSUES[@]}" | sort | tr '\n' '|')
 prev=""

src/components/CoordinatorSettingsCard.tsx

@@ -13,6 +13,7 @@ import {
 import { Button } from '@/components/ui/button';
 import { Input } from '@/components/ui/input';
 import { QRCodeCanvas } from '@/components/ui/qrcode';
+import { useRelayStatus } from '@/hooks/useRelayStatus';
 import { QRScannerModal } from '@/components/wallet/QRScannerModal';
 import { useCoordinator, useCoordinatorHealth, type CoordinatorHealthStatus } from '@/hooks/useCoordinator';
 import { useTranslation } from '@/contexts/language';
@@ -27,6 +28,7 @@ import {
   SKATESPOTS_COORDINATOR,
 } from '@/lib/coordinator';
 import { cn } from '@/lib/utils';
+import { urlDomain } from '@/lib/sanitizeUrl';
 
 function timeAgo(unixSeconds: number, t: (key: string, params?: Record<string, string | number>) => string): string {
   const s = Math.floor(Date.now() / 1000 - unixSeconds);
@@ -59,6 +61,28 @@ async function copyText(text: string, copiedText: string, failedTitle: string, f
   }
 }
 
+/** Small live health pill for one relay. Probes only while this card is open. */
+function RelayHealthPill({ url }: { url: string }) {
+  const { status, reason, recheck } = useRelayStatus(url);
+  const dot =
+    status === 'connected'
+      ? 'bg-green-400'
+      : status === 'connecting'
+        ? 'bg-blue-400 animate-pulse'
+        : 'bg-red-400';
+  return (
+    <button
+      type="button"
+      onClick={recheck}
+      title={reason ?? status}
+      className="inline-flex max-w-full items-center gap-1.5 rounded-full border border-white/10 bg-white/[0.03] px-2 py-1 text-[10px] text-gray-400 transition-colors hover:border-white/20 hover:text-gray-200"
+    >
+      <span className={cn('h-1.5 w-1.5 shrink-0 rounded-full', dot)} />
+      <span className="truncate">{urlDomain(url)}</span>
+    </button>
+  );
+}
+
 /**
  * Settings → Coordinator.
  *
@@ -119,6 +143,11 @@ export function CoordinatorSettingsCard() {
                   : t('socialUi.coordinator.relayMany', { count: coordinator.relays.length })}
                 {lastSeen ? ` · ${t('socialUi.coordinator.lastSeen', { time: timeAgo(lastSeen, t) })}` : ''}
               </p>
+              {coordinator.relays.length > 0 && (
+                <div className="mt-2 flex flex-wrap gap-1.5">
+                  {coordinator.relays.map((url) => <RelayHealthPill key={url} url={url} />)}
+                </div>
+              )}
             </div>
             <span
               className={cn(

src/components/crew/CrewCoordinatorCard.tsx

@@ -1,7 +1,9 @@
+import { useState } from 'react';
 import { Link } from 'react-router-dom';
-import { Lock, ShieldCheck, Server, ExternalLink, Settings, Copy, MessagesSquare, Users } from 'lucide-react';
+import { Lock, ShieldCheck, Server, ExternalLink, Settings, Copy, MessagesSquare, Users, QrCode } from 'lucide-react';
 import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
 import { Avatar, AvatarFallback, AvatarImage } from '@/components/ui/avatar';
+import { QRCodeCanvas } from '@/components/ui/qrcode';
 import { useAuthor } from '@/hooks/useAuthor';
 import { useTranslation } from '@/contexts/language';
 import { useToast } from '@/hooks/useToast';
@@ -217,6 +219,7 @@ export function CrewCoordinatorCard({
 function StaircaseLink({ coordinator }: { coordinator: { pubkey?: string; relays?: string[] } }) {
   const { t } = useTranslation();
   const { toast } = useToast();
+  const [showQr, setShowQr] = useState(false);
   const nprofile = coordinator.pubkey
     ? nip19.nprofileEncode({ pubkey: coordinator.pubkey, relays: coordinator.relays ?? [] })
     : null;
@@ -247,6 +250,7 @@ function StaircaseLink({ coordinator }: { coordinator: { pubkey?: string; relays
         <ExternalLink className="h-3.5 w-3.5" /> {t('socialUi.crewCoordinator.openInCordnWeb')}
       </a>
       {nprofile && (
+        <>
           <button
             type="button"
             onClick={() => void copyNprofile()}
@@ -254,6 +258,23 @@ function StaircaseLink({ coordinator }: { coordinator: { pubkey?: string; relays
           >
             <Copy className="h-3.5 w-3.5" /> {t('socialUi.crewCoordinator.copyForStaircase')}
           </button>
+          <button
+            type="button"
+            onClick={() => setShowQr((v) => !v)}
+            aria-expanded={showQr}
+            className={`${btn} border-white/15 bg-white/5 text-gray-300 hover:bg-white/10`}
+          >
+            <QrCode className="h-3.5 w-3.5" /> QR
+          </button>
+        </>
+      )}
+      {showQr && nprofile && (
+        <div className="mt-2 flex w-full flex-col items-center gap-2 rounded-xl border border-white/10 bg-black/40 p-3">
+          <QRCodeCanvas value={nprofile} size={168} level="M" />
+          <p className="text-center text-[11px] text-gray-500">
+            {t('socialUi.coordinator.scanToJoin')}
+          </p>
+        </div>
       )}
     </>
   );

src/hooks/useCordnNative.ts

@@ -71,7 +71,7 @@ export interface UseCordnNativeResult {
   /** Send a read receipt for an inbound message. */
   markRead: (messageId: string) => Promise<boolean>;
   /** Re-fetch messages (and adopt any new commits). */
-  refresh: () => Promise<void>;
+  refresh: () => Promise<boolean>;
   /** Founder/admin: create the crew's MLS group. */
   createChat: () => Promise<boolean>;
   /** Non-admin: ask the coordinator to be added (publishes a key package). */
@@ -110,6 +110,8 @@ export interface UseCordnNativeResult {
 }
 
 const POLL_MS = 6000;
+const HIDDEN_POLL_MS = 12000;
+const MAX_BACKOFF_MS = 60000;
 
 /**
  * Drives a {@link CordnSession} for one crew: real MLS over the crew's Cordn
@@ -231,9 +233,9 @@ export function useCordnNative({
     };
   }, [enabled, pubkey, signer, coordinator, groupId, reloadKey]);
 
-  const refresh = useCallback(async () => {
+  const refresh = useCallback(async (): Promise<boolean> => {
     const session = sessionRef.current;
-    if (!session || !group) return;
+    if (!session || !group) return false;
     try {
       await session.fetch(group.gid);
       const next = session.messages(group.gid);
@@ -241,20 +243,47 @@ export function useCordnNative({
       setGroup(session.listGroups().find((g) => g.gid === group.gid) ?? group);
       setError(null);
       setLastCheckedAt(Date.now());
+      return true;
     } catch (err) {
       setError(err instanceof Error ? err.message : String(err));
       setLastCheckedAt(Date.now());
+      return false;
     }
   }, [group]);
 
   // Live polling for silent signers only — an interactive signer would pop for
   // every request, so those users refresh/send manually (same rule as the DM
-  // and sealed-relay chat hooks).
+  // and sealed-relay chat hooks). Hidden tabs poll less, and a failure backs
+  // off exponentially with jitter so a busy/rate-limited coordinator is not
+  // hammered by every open device.
+  const pollDelayRef = useRef(POLL_MS);
   useEffect(() => {
     if (!ready || !group || interactive || !canBackgroundPoll) return;
-    const id = setInterval(() => void refresh(), POLL_MS);
+    let cancelled = false;
-    return () => clearInterval(id);
+    let timer: ReturnType<typeof setTimeout> | undefined;
-  }, [ready, group, interactive, canBackgroundPoll, refresh]);
+    pollDelayRef.current = active ? POLL_MS : HIDDEN_POLL_MS;
+
+    const tick = async () => {
+      const ok = await refresh();
+      if (cancelled) return;
+      if (ok) {
+        pollDelayRef.current = active ? POLL_MS : HIDDEN_POLL_MS;
+      } else {
+        pollDelayRef.current = Math.min(
+          MAX_BACKOFF_MS,
+          Math.max(POLL_MS, Math.round(pollDelayRef.current * 1.7)),
+        );
+      }
+      const jitter = Math.round(Math.random() * 800);
+      timer = setTimeout(() => void tick(), pollDelayRef.current + jitter);
+    };
+
+    timer = setTimeout(() => void tick(), pollDelayRef.current);
+    return () => {
+      cancelled = true;
+      if (timer) clearTimeout(timer);
+    };
+  }, [ready, group, interactive, canBackgroundPoll, active, refresh]);
 
   // One coordinator operation at a time. With Amber every coordinator request
   // is a foreground approval; a double-tap on "Set up" used to start two