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.

web/vite.config.ts

@@ -6,7 +6,11 @@ import { defineConfig } from 'vite'
 // the app always talks to a relative `/api` base. During development Vite
 // proxies that prefix to a locally running fancy-dns.
 export default defineConfig({
-  base: './',
+  // BrowserRouter routes such as /auth/login are served by the SPA fallback.
+  // A relative base makes their asset URLs resolve under /auth/assets, which
+  // the fallback answers with index.html and leaves the page blank. Rooted
+  // URLs keep assets and API calls on the application origin at every route.
+  base: '/',
   plugins: [react(), tailwindcss()],
   server: {
     proxy: {