feat(cli): branded top bar with mosaic windmill icon

- ASCII art mosaic windmill: 4 colored tiles (blue, purple, teal, amber)
  with pink center, matching the Mosaic Stack brand
- 3-line info block (Claude Code style):
  Line 1: 'Mosaic Stack v0.0.0'
  Line 2: model (context) · thinking · agent name
  Line 3: ● host connection status
- Remove bordered box in favor of open layout with icon

packages/cli/src/tui/app.tsx

@@ -43,7 +43,16 @@ export function TuiApp({ gatewayUrl, conversationId, sessionCookie }: TuiAppProp
 
   return (
     <Box flexDirection="column" height="100%">
-      <TopBar gatewayUrl={gatewayUrl} />
+      <TopBar
+        gatewayUrl={gatewayUrl}
+        version="0.0.0"
+        modelName={socket.modelName}
+        thinkingLevel={socket.thinkingLevel}
+        contextWindow={socket.tokenUsage.contextWindow}
+        agentName="default"
+        connected={socket.connected}
+        connecting={socket.connecting}
+      />
 
       <MessageList
         messages={socket.messages}