UX/UI/perf pass: admin tabs, theme toggle, log polish, mod search, JAR cache

- Admin page split into tabs (Server/Players/Chat/Mods/Backups/Logs) with
  hash + localStorage persistence; inactive tabs no longer mount.
- Log viewer: level color-coding, search, level filter chips, auto-scroll
  toggle, copy button, visible-line count.
- Installed mods list: search field + side filter (all/both/server/client)
  with live count; public ModList gets skeleton + empty states and search.
- Theme toggle with no-flash inline init, localStorage + system preference.
- Layout: full OG / Twitter metadata, title template, keywords,
  dual-theme themeColor, metadataBase.
- lib/mods.ts: per-jar mtime+size parse cache (cold 6s -> warm ~45ms on
  /api/mods for the full mod list); cache eviction on mod removal.
- ChatBridge polling eased 3s -> 5s with 2s stale window.

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

components/AdminTabs.tsx

@@ -0,0 +1,80 @@
+"use client";
+
+import { useEffect, useState } from "react";
+import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
+import { ServerControls } from "@/components/ServerControls";
+import { Analytics } from "@/components/Analytics";
+import { PlayerManager } from "@/components/PlayerManager";
+import { ChatBridge } from "@/components/ChatBridge";
+import { ModManager } from "@/components/ModManager";
+import { BackupManager } from "@/components/BackupManager";
+import { LogViewer } from "@/components/LogViewer";
+
+const TABS = [
+  { value: "server", label: "Server" },
+  { value: "players", label: "Players" },
+  { value: "chat", label: "Chat" },
+  { value: "mods", label: "Mods" },
+  { value: "backups", label: "Backups" },
+  { value: "logs", label: "Logs" },
+];
+
+export function AdminTabs() {
+  const [mounted, setMounted] = useState(false);
+  const [value, setValue] = useState<string>("server");
+
+  useEffect(() => {
+    setMounted(true);
+    const hash = window.location.hash.replace("#", "");
+    if (hash && TABS.some((t) => t.value === hash)) {
+      setValue(hash);
+      return;
+    }
+    const saved = localStorage.getItem("admin-tab");
+    if (saved && TABS.some((t) => t.value === saved)) setValue(saved);
+  }, []);
+
+  useEffect(() => {
+    if (!mounted) return;
+    localStorage.setItem("admin-tab", value);
+    history.replaceState(null, "", `#${value}`);
+  }, [value, mounted]);
+
+  if (!mounted) return null;
+
+  return (
+    <Tabs
+      value={value}
+      onValueChange={(v) => setValue(v as string)}
+      className="w-full"
+    >
+      <TabsList className="flex w-full flex-wrap h-auto sm:h-9 gap-1 p-1 overflow-x-auto justify-start sm:justify-center">
+        {TABS.map((t) => (
+          <TabsTrigger key={t.value} value={t.value} className="text-xs sm:text-sm">
+            {t.label}
+          </TabsTrigger>
+        ))}
+      </TabsList>
+
+      <TabsContent value="server" className="mt-4 space-y-4 sm:space-y-6">
+        <ServerControls />
+        <Analytics />
+      </TabsContent>
+      <TabsContent value="players" className="mt-4">
+        <PlayerManager />
+      </TabsContent>
+      <TabsContent value="chat" className="mt-4" keepMounted={false}>
+        <ChatBridge />
+      </TabsContent>
+      <TabsContent value="mods" className="mt-4">
+        <ModManager />
+      </TabsContent>
+      <TabsContent value="backups" className="mt-4">
+        <BackupManager />
+      </TabsContent>
+      <TabsContent value="logs" className="mt-4" keepMounted={false}>
+        <LogViewer />
+      </TabsContent>
+    </Tabs>
+  );
+}