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>

app/api/mods/route.ts

@@ -6,7 +6,9 @@ export const dynamic = "force-dynamic";
 export async function GET() {
   try {
     const mods = getModDetails();
-    return NextResponse.json(mods);
+    return NextResponse.json(mods, {
+      headers: { "Cache-Control": "public, max-age=10" },
+    });
   } catch (e) {
     return NextResponse.json(
       { error: (e as Error).message },