feat: add Stirling-PDF-style layout with sidebar, tool panel, dropzone, and theme toggle

apps/web/src/App.tsx

@@ -1,10 +1,11 @@
 import { BrowserRouter, Routes, Route } from "react-router-dom";
+import { HomePage } from "./pages/home-page";
 
 export function App() {
   return (
     <BrowserRouter>
       <Routes>
-        <Route path="/" element={<div className="p-8 text-2xl font-bold text-primary">Stirling Image</div>} />
+        <Route path="/" element={<HomePage />} />
       </Routes>
     </BrowserRouter>
   );