Vite demo config: load env files from repo root

Vite's default envDir is the `root` option, which here points into
`src/demo/apps/<slice>/` — no env files live there, so the Google Maps
API key from `.env.local` never made it into the production bundle and
ProviderMap silently fell back to its "no API key" empty state on
parsons.tensordesign.com.au. Set envDir to the repo root so `.env` and
`.env.local` are picked up.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

vite.demo.config.ts

@@ -16,6 +16,12 @@ export default defineConfig(({ mode, command }) => {
 
   return {
     root: appRoot,
+    // Load `.env` / `.env.local` from the repo root. Vite's default is to
+    // read env files from `root`, which here points into `src/demo/apps/...`
+    // where no env files live — so without this VITE_GOOGLE_MAPS_API_KEY
+    // never reaches the built bundle and ProviderMap silently falls back
+    // to its "no API key" empty state in production.
+    envDir: __dirname,
     // Dev server uses absolute base so HMR/asset URLs work at the root;
     // production build prefixes assets with /<slice>/ so the bundle is
     // portable to any nginx location matching that path.