debug: red background test to check renderer loading

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Elec/src/renderer/src/App.tsx

@@ -9,7 +9,7 @@ export default function App() {
   const [activeModel, setActiveModel] = useState<Model>('Deepseek')
 
   return (
-    <div className="flex flex-col h-full bg-black">
+    <div className="flex flex-col h-full" style={{ background: '#ff0000' }}>
       <ModelSelector active={activeModel} onSelect={setActiveModel} />
       <ChatArea />
       <InputArea />

Elec/src/renderer/src/index.css

@@ -8,8 +8,8 @@
 
 html, body, #root {
   height: 100%;
-  background: #000;
-  color: #e5e5e5;
+  background: #ff0000;
+  color: #fff;
   font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", sans-serif;
   -webkit-font-smoothing: antialiased;
   overflow: hidden;