feat: add multi-server control panel and host-aware sync

app/web/static/js/server-config.js

@@ -0,0 +1,99 @@
+const SERVER_STORAGE_KEY = "llm_monitor_servers";
+const ACTIVE_SERVER_KEY = "llm_monitor_active_server";
+
+function normalizeHost(host) {
+  if (!host) {
+    return "";
+  }
+
+  const trimmed = host.trim();
+  if (!trimmed) {
+    return "";
+  }
+
+  return trimmed.replace(/\/+$/, "");
+}
+
+function loadServers() {
+  const raw = localStorage.getItem(SERVER_STORAGE_KEY);
+  if (!raw) {
+    return [];
+  }
+
+  try {
+    const parsed = JSON.parse(raw);
+    if (!Array.isArray(parsed)) {
+      return [];
+    }
+
+    return parsed
+      .map((item) => ({
+        id: String(item.id || ""),
+        name: String(item.name || "").trim(),
+        host: normalizeHost(item.host || "")
+      }))
+      .filter((item) => item.id && item.name && item.host);
+  } catch {
+    return [];
+  }
+}
+
+function saveServers(servers) {
+  localStorage.setItem(SERVER_STORAGE_KEY, JSON.stringify(servers));
+}
+
+function generateServerId() {
+  return `srv_${Date.now()}_${Math.random().toString(16).slice(2, 8)}`;
+}
+
+function getActiveServerId() {
+  return localStorage.getItem(ACTIVE_SERVER_KEY);
+}
+
+function setActiveServerId(serverId) {
+  localStorage.setItem(ACTIVE_SERVER_KEY, serverId);
+}
+
+function getServerById(serverId) {
+  return loadServers().find((server) => server.id === serverId) || null;
+}
+
+function getServerIdFromQuery() {
+  const params = new URLSearchParams(window.location.search);
+  return params.get("server") || "";
+}
+
+function getActiveServer() {
+  const queryServerId = getServerIdFromQuery();
+  if (queryServerId) {
+    const fromQuery = getServerById(queryServerId);
+    if (fromQuery) {
+      setActiveServerId(fromQuery.id);
+      return fromQuery;
+    }
+  }
+
+  const activeServerId = getActiveServerId();
+  if (activeServerId) {
+    const activeServer = getServerById(activeServerId);
+    if (activeServer) {
+      return activeServer;
+    }
+  }
+
+  const servers = loadServers();
+  if (servers.length > 0) {
+    setActiveServerId(servers[0].id);
+    return servers[0];
+  }
+
+  return null;
+}
+
+function buildServerUrl(path, serverId) {
+  const url = new URL(path, window.location.origin);
+  if (serverId) {
+    url.searchParams.set("server", serverId);
+  }
+  return `${url.pathname}${url.search}`;
+}