Fix console assets on nested routes

The relative Vite base made BrowserRouter pages request JavaScript and CSS under /auth/assets. The SPA fallback returned index.html for those paths, so the browser never mounted React and the sign-in page appeared blank. Emit root-relative asset URLs so every client-side route loads the embedded console bundle.

internal/web/dist/index.html

@@ -2,11 +2,11 @@
 <html lang="en">
   <head>
     <meta charset="UTF-8" />
-    <link rel="icon" type="image/svg+xml" href="./favicon.svg" />
+    <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>web</title>
-    <script type="module" crossorigin src="./assets/index-Dh5C0Ucn.js"></script>
-    <link rel="stylesheet" crossorigin href="./assets/index-CZ8p4VMZ.css">
+    <script type="module" crossorigin src="/assets/index-D_F84V7q.js"></script>
+    <link rel="stylesheet" crossorigin href="/assets/index-CZ8p4VMZ.css">
   </head>
   <body>
     <div id="root"></div>