feat(ui): chat/MCPConnectPicker to shadcn

- antd Switch/Spin \u2192 shadcn Switch + lucide Loader2 (replacing the
  Switch's loading prop with a separate inline spinner since shadcn
  Switch has no loading slot).
- Inline style attributes replaced with Tailwind utilities + semantic
  tokens (text-muted-foreground / text-foreground).

Gates: TS \u2713 | Build \u2713.

Co-authored-by: yuneng-jiang <yuneng-berri@users.noreply.github.com>

ui/litellm-dashboard/src/components/chat/MCPConnectPicker.tsx

@@ -1,5 +1,6 @@
 import React, { useEffect, useState } from "react";
-import { Switch, Spin } from "antd";
+import { Switch } from "@/components/ui/switch";
+import { Loader2 } from "lucide-react";
 import MessageManager from "@/components/molecules/message_manager";
 import { fetchMCPServers, listMCPTools } from "../networking";
 import { MCPServer } from "../mcp_tools/types";
@@ -10,10 +11,13 @@ interface Props {
   onChange: (servers: string[]) => void;
 }
 
-const MCPConnectPicker: React.FC<Props> = ({ accessToken, selectedServers, onChange }) => {
+const MCPConnectPicker: React.FC<Props> = ({
+  accessToken,
+  selectedServers,
+  onChange,
+}) => {
   const [servers, setServers] = useState<MCPServer[]>([]);
   const [loadingServers, setLoadingServers] = useState(true);
-  // Track which individual servers are being toggled on (verifying tools)
   const [togglingOn, setTogglingOn] = useState<Set<string>>(new Set());
 
   useEffect(() => {
@@ -24,8 +28,9 @@ const MCPConnectPicker: React.FC<Props> = ({ accessToken, selectedServers, onCha
       try {
         const data = await fetchMCPServers(accessToken);
         if (cancelled) return;
-        // API returns { data: MCPServer[] } or MCPServer[]
-        const list: MCPServer[] = Array.isArray(data) ? data : (data?.data ?? []);
+        const list: MCPServer[] = Array.isArray(data)
+          ? data
+          : (data?.data ?? []);
         setServers(list);
       } catch {
         if (!cancelled) {
@@ -47,29 +52,24 @@ const MCPConnectPicker: React.FC<Props> = ({ accessToken, selectedServers, onCha
 
   const handleToggle = async (serverName: string, checked: boolean) => {
     if (!checked) {
-      // Toggle OFF — remove immediately, no tool fetch needed
       onChange(selectedServers.filter((s) => s !== serverName));
       return;
     }
 
-    // Toggle ON — verify tools are reachable first
     setTogglingOn((prev) => new Set(prev).add(serverName));
     try {
       const result = await listMCPTools(accessToken, serverName);
-      // listMCPTools never throws; it returns { tools, error, message } on failure
       if (result?.error) {
         MessageManager.warning(
-          `Could not load tools for ${serverName} — it will be excluded from this message.`
+          `Could not load tools for ${serverName} — it will be excluded from this message.`,
         );
-        // Do not add to selectedServers
         return;
       }
       onChange([...selectedServers, serverName]);
     } catch {
       MessageManager.warning(
-        `Could not load tools for ${serverName} — it will be excluded from this message.`
+        `Could not load tools for ${serverName} — it will be excluded from this message.`,
       );
-      // Do not add to selectedServers
     } finally {
       setTogglingOn((prev) => {
         const next = new Set(prev);
@@ -80,20 +80,13 @@ const MCPConnectPicker: React.FC<Props> = ({ accessToken, selectedServers, onCha
   };
 
   return (
-    <div
-      style={{
-        maxWidth: 320,
-        maxHeight: 400,
-        overflowY: "auto",
-        padding: "8px 0",
-      }}
-    >
+    <div className="max-w-[320px] max-h-[400px] overflow-y-auto py-2">
       {loadingServers ? (
-        <div style={{ display: "flex", justifyContent: "center", padding: "24px 0" }}>
-          <Spin />
+        <div className="flex justify-center py-6">
+          <Loader2 className="h-4 w-4 animate-spin text-muted-foreground" />
         </div>
       ) : servers.length === 0 ? (
-        <div style={{ padding: "16px 12px", color: "#8c8c8c", fontSize: 13, textAlign: "center" }}>
+        <div className="px-3 py-4 text-muted-foreground text-sm text-center">
           No MCP servers configured
         </div>
       ) : (
@@ -105,60 +98,39 @@ const MCPConnectPicker: React.FC<Props> = ({ accessToken, selectedServers, onCha
           return (
             <div
               key={server.server_id}
-              style={{
-                display: "flex",
-                alignItems: "flex-start",
-                justifyContent: "space-between",
-                padding: "8px 12px",
-                gap: 12,
-              }}
+              className="flex items-start justify-between px-3 py-2 gap-3"
             >
               {server.mcp_info?.logo_url && (
+                // eslint-disable-next-line @next/next/no-img-element
                 <img
                   src={server.mcp_info.logo_url}
                   alt={`${name} logo`}
-                  style={{
-                    width: 24, height: 24, borderRadius: 6,
-                    objectFit: "contain", flexShrink: 0,
-                    marginTop: 1,
+                  className="w-6 h-6 rounded-md object-contain shrink-0 mt-0.5"
+                  onError={(e) => {
+                    (e.target as HTMLImageElement).style.display = "none";
                   }}
-                  onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }}
                 />
               )}
-              <div style={{ flex: 1, minWidth: 0 }}>
-                <div
-                  style={{
-                    fontWeight: 500,
-                    fontSize: 13,
-                    color: "#1f1f1f",
-                    whiteSpace: "nowrap",
-                    overflow: "hidden",
-                    textOverflow: "ellipsis",
-                  }}
-                >
+              <div className="flex-1 min-w-0">
+                <div className="font-medium text-sm text-foreground truncate">
                   {name}
                 </div>
                 {server.description && (
-                  <div
-                    style={{
-                      fontSize: 12,
-                      color: "#8c8c8c",
-                      marginTop: 2,
-                      whiteSpace: "nowrap",
-                      overflow: "hidden",
-                      textOverflow: "ellipsis",
-                    }}
-                  >
+                  <div className="text-xs text-muted-foreground mt-0.5 truncate">
                     {server.description}
                   </div>
                 )}
               </div>
-              <Switch
-                size="small"
-                checked={isSelected}
-                loading={isTogglingOn}
-                onChange={(checked) => handleToggle(name, checked)}
-              />
+              <div className="flex items-center">
+                {isTogglingOn && (
+                  <Loader2 className="h-3 w-3 animate-spin text-muted-foreground mr-1" />
+                )}
+                <Switch
+                  checked={isSelected}
+                  onCheckedChange={(checked) => handleToggle(name, checked)}
+                  disabled={isTogglingOn}
+                />
+              </div>
             </div>
           );
         })