test(gate): fix the last 4 readiness/config false-fails (none are product bugs)

On a proper on-node .228 run (synced bitcoin, 4-fix binary) the lifecycle matrix is
green; these 4 were test-harness issues:
- lnd 'recovers after restart' (65): bump retry window 90s->240s. lnd cold-restart
  recovery (wallet unlock + bitcoind reconnect + graph sync) exceeds 90s on a loaded
  node but DOES complete (synced_to_chain:true).
- bitcoin ui responds (89): retry ~120s instead of single-shot (companion nginx may
  have just been recreated by the companion-survives test).
- probe_app_url (99 lnd proxy + all ui-coverage proxy probes): retry up to 90s for
  post-restart proxy/UI readiness instead of single-shot.
- required endpoints after restart (94): :8081 is nginx-proxy-manager, an OPTIONAL
  app (not in required_containers) — only assert it when NPM is installed; and make
  the trailing lncli getinfo a retry.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/lifecycle/lib/ui-probes.bash

@@ -65,6 +65,16 @@ probe_app_url() {
   if ! probe_container_running "$container"; then
     skip "$label: backing container '$container' is not running"
   fi
+  # An app's proxy/UI takes time to serve 200 after a (re)start — the backend
+  # may still be unlocking/syncing (lnd) and the companion nginx reloading.
+  # Retry up to ~90s rather than single-shot, so a readiness race isn't a fail.
+  local deadline=$(( $(date +%s) + 90 ))
+  while (( $(date +%s) < deadline )); do
+    if probe_https_200 "$url" "$label"; then
+      return 0
+    fi
+    sleep 3
+  done
   run probe_https_200 "$url" "$label"
   [ "$status" -eq 0 ]
 }