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/bats/required-stack.bats

@@ -123,7 +123,10 @@ PY
 }
 
 @test "bitcoin ui responds" {
-  run curl -fsS "http://127.0.0.1:8334/"
+  # The companion (archy-bitcoin-ui) may have just been recreated by an earlier
+  # companion-survives test; its nginx takes a moment to serve. Retry ~120s
+  # rather than single-shot.
+  run sh -lc 'for i in $(seq 1 40); do curl -fsS -o /dev/null "http://127.0.0.1:8334/" && exit 0; sleep 3; done; exit 1'
   [ "$status" -eq 0 ]
 }