Fix API paths and make hotel name configurable

- /api/notices → /notices/api/notices to match nginx location block
  (was returning portal index.html causing JSON parse error)
- Add VITE_HOTEL_NAME build arg, remove hardcoded hotel name
- Add vite-env.d.ts for TypeScript import.meta.env support

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/Dockerfile

@@ -3,6 +3,8 @@ WORKDIR /app
 COPY package.json .
 RUN npm install
 COPY . .
+ARG VITE_HOTEL_NAME="Number Four at Stow"
+ENV VITE_HOTEL_NAME=$VITE_HOTEL_NAME
 RUN npm run build
 
 FROM nginx:alpine