Performance: RCON pooling, route caching, parallel status probe

Server:
- lib/cache.ts: tiny TTL memo for hot paths.
- lib/rcon.ts: pooled connection with 30s idle close and one-shot retry;
  was opening a fresh TCP per RCON call.
- /api/status: race protocol-ping + RCON with Promise.any (was sequential
  with 5s timeouts) and memo 3s; adds Cache-Control.
- /api/players: memo 10s, invalidated on mutations.
- /api/mods: getModDetails memo 10s (invalidated on install/remove) —
  eliminates per-request readdirSync/statSync/AdmZip parse.
- /api/analytics: reverse-scan JSONL to window cutoff (O(window) vs O(file))
  and memo 30s.
- /api/logs: memo 2s to throttle journalctl spawns during Live mode.

Client:
- StatusCard + ServerControls: staleTime 5s, both poll every 10s, dedup
  via shared query key.
- Analytics: staleTime 30s; memoize sparkline SVG paths.
- Modrinth search icons + mc-heads avatars: width/height + loading=lazy +
  decoding=async.
- next.config.ts: images.remotePatterns for future next/image migration,
  explicit compress=true.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

components/ServerControls.tsx

@@ -39,6 +39,7 @@ export function ServerControls() {
     queryKey: ["status"],
     queryFn: () => fetch("/api/status").then((r) => r.json()),
     refetchInterval: 10000,
+    staleTime: 5000,
   });
 
   const action = useMutation({