feat(mcp): add Model Context Protocol integration

Add  MCP integration including:
- New MCP settings tab with server configuration
- Tool invocation UI components
- API endpoints for MCP management
- Integration with chat system for tool execution
- Example configurations

app/components/@settings/core/ControlPanel.tsx

@@ -33,7 +33,7 @@ interface ControlPanelProps {
 }
 
 // Beta status for experimental features
-const BETA_TABS = new Set<TabType>(['service-status', 'local-providers']);
+const BETA_TABS = new Set<TabType>(['service-status', 'local-providers', 'mcp']);
 
 const BetaLabel = () => (
   <div className="absolute top-2 right-2 px-1.5 py-0.5 rounded-full bg-purple-500/10 dark:bg-purple-500/20">

app/components/@settings/core/constants.ts

@@ -9,8 +9,8 @@ export const TAB_ICONS: Record<TabType, string> = {
   'cloud-providers': 'i-ph:cloud',
   'local-providers': 'i-ph:laptop',
   'service-status': 'i-ph:activity-bold',
-  connection: 'i-ph:wifi-high-fill',
-  'event-logs': 'i-ph:list-bullets-fill',
+  connection: 'i-ph:wifi-high',
+  'event-logs': 'i-ph:list-bullets',
   mcp: 'i-ph:hard-drives-bold',
 };
 
@@ -53,7 +53,8 @@ export const DEFAULT_TAB_CONFIG = [
   { id: 'event-logs', visible: true, window: 'user' as const, order: 6 },
   { id: 'mcp', visible: true, window: 'user' as const, order: 7 },
   { id: 'profile', visible: true, window: 'user' as const, order: 8 },
-  { id: 'settings', visible: true, window: 'user' as const, order: 9 },
-  { id: 'service-status', visible: true, window: 'user' as const, order: 10 },
-  { id: 'update', visible: true, window: 'user' as const, order: 11 },
+  { id: 'service-status', visible: true, window: 'user' as const, order: 9 },
+
+  // User Window Tabs (In dropdown, initially hidden)
+  { id: 'settings', visible: false, window: 'user' as const, order: 10 },
 ];

app/components/chat/Chat.client.tsx

@@ -28,6 +28,8 @@ import type { ElementInfo } from '~/components/workbench/Inspector';
 import type { TextUIPart, FileUIPart, Attachment } from '@ai-sdk/ui-utils';
 import { useMCPStore } from '~/lib/stores/mcp';
 import type { LlmErrorAlertType } from '~/types/actions';
+import type { TextUIPart, FileUIPart, Attachment } from '@ai-sdk/ui-utils';
+import { useMCPStore } from '~/lib/stores/mcp';
 
 const toastAnimation = cssTransition({
   enter: 'animated fadeInRight',