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/analytics/route.ts

@@ -1,6 +1,7 @@
 import { NextRequest, NextResponse } from "next/server";
 import { readFileSync, existsSync } from "fs";
 import { auth } from "@/lib/auth";
+import { memo } from "@/lib/cache";
 
 export const dynamic = "force-dynamic";
 
@@ -16,6 +17,27 @@ type MetricEntry = {
   players: string[];
 };
 
+function readWindow(hours: number): MetricEntry[] {
+  const cutoff = new Date(Date.now() - hours * 60 * 60 * 1000).toISOString();
+  const raw = readFileSync(ANALYTICS_FILE, "utf8");
+
+  // Reverse scan: walk from the end, collect until we pass cutoff.
+  const out: MetricEntry[] = [];
+  let end = raw.length;
+  while (end > 0) {
+    const start = raw.lastIndexOf("\n", end - 1);
+    const line = raw.slice(start + 1, end).trim();
+    end = start;
+    if (!line) continue;
+    try {
+      const entry = JSON.parse(line) as MetricEntry;
+      if (entry.ts < cutoff) break; // file is append-ordered by time
+      out.push(entry);
+    } catch {}
+  }
+  return out.reverse();
+}
+
 export async function GET(req: NextRequest) {
   const session = await auth();
   if (!session) {
@@ -32,21 +54,10 @@ export async function GET(req: NextRequest) {
   }
 
   try {
-    const lines = readFileSync(ANALYTICS_FILE, "utf8")
-      .split("\n")
-      .filter(Boolean);
-
-    const cutoff = new Date(Date.now() - hours * 60 * 60 * 1000).toISOString();
-
-    const entries: MetricEntry[] = [];
-    for (const line of lines) {
-      try {
-        const entry = JSON.parse(line) as MetricEntry;
-        if (entry.ts >= cutoff) entries.push(entry);
-      } catch {}
-    }
-
-    return NextResponse.json(entries);
+    const entries = memo(`analytics:${hours}`, 30_000, () => readWindow(hours));
+    return NextResponse.json(entries, {
+      headers: { "Cache-Control": "private, max-age=30" },
+    });
   } catch (e) {
     return NextResponse.json(
       { error: (e as Error).message },