refactor(mcp): improve UI consistency and i18n

- Add MCP-specific green button style (buttonStyles.mcp)
- Unify MCP panel and form buttons with emerald theme
- Adjust MCP entry button width to match AppSwitcher (px-3)
- Reduce JSON editor height from h-64 to h-48
- Update translations: "Add/Edit Server" → "Add/Edit MCP"
- Change form label to "MCP Title (Unique)" for clarity
- Move config wizard button to right side of JSON label
- Fix McpListItem enabled state check (explicit true check)

src/components/mcp/McpFormModal.tsx

@@ -244,13 +244,13 @@ const McpFormModal: React.FC<McpFormModalProps> = ({
               <button
                 type="button"
                 onClick={() => setIsWizardOpen(true)}
-                className="text-xs text-blue-500 dark:text-blue-400 hover:text-blue-600 dark:hover:text-blue-300 transition-colors"
+                className="text-sm text-blue-500 dark:text-blue-400 hover:text-blue-600 dark:hover:text-blue-300 transition-colors"
               >
                 {t("mcp.form.useWizard")}
               </button>
             </div>
             <textarea
-              className={`${inputStyles.text} h-64 resize-none font-mono text-xs`}
+              className={`${inputStyles.text} h-48 resize-none font-mono text-xs`}
               placeholder={t("mcp.form.jsonPlaceholder")}
               value={formJson}
               onChange={(e) => handleJsonChange(e.target.value)}
@@ -272,7 +272,7 @@ const McpFormModal: React.FC<McpFormModalProps> = ({
           <button
             onClick={handleSubmit}
             disabled={saving || (!isEditing && !!idError)}
-            className={buttonStyles.primary}
+            className={`inline-flex items-center gap-2 ${buttonStyles.mcp}`}
           >
             <Save size={16} />
             {saving

src/components/mcp/McpListItem.tsx

@@ -26,8 +26,8 @@ const McpListItem: React.FC<McpListItemProps> = ({
 }) => {
   const { t } = useTranslation();
 
-  // 默认启用
-  const enabled = server.enabled !== false;
+  // 仅当显式为 true 时视为启用；避免 undefined 被误判为启用
+  const enabled = server.enabled === true;
 
   // 只显示 description，没有则留空
   const description = (server as any).description || "";

src/components/mcp/McpPanel.tsx

@@ -8,7 +8,7 @@ import { ConfirmDialog } from "../ConfirmDialog";
 import { extractErrorMessage } from "../../utils/errorUtils";
 import { mcpPresets } from "../../config/mcpPresets";
 import McpToggle from "./McpToggle";
-import { cardStyles, cn } from "../../lib/styles";
+import { buttonStyles, cardStyles, cn } from "../../lib/styles";
 
 interface McpPanelProps {
   onClose: () => void;
@@ -178,7 +178,7 @@ const McpPanel: React.FC<McpPanelProps> = ({ onClose, onNotify }) => {
           <div className="flex items-center gap-3">
             <button
               onClick={handleAdd}
-              className="inline-flex items-center gap-2 px-4 py-2 text-sm font-medium rounded-md bg-emerald-500 text-white hover:bg-emerald-600 dark:bg-emerald-600 dark:hover:bg-emerald-700 transition-colors"
+              className={`inline-flex items-center gap-2 ${buttonStyles.mcp}`}
             >
               <Plus size={16} />
               {t("mcp.add")}