Fix production base path and ProxyPass docs for /generadorexamenesllm.

This removes the incorrect /deckofcars prefix, aligns CI/build defaults with the real public URL, and adds an Apache ProxyPass snippet so the request is routed to the Docker frontend instead of the Sinbad2 site.

frontend/Dockerfile

@@ -2,7 +2,7 @@
 FROM node:20-alpine AS build
 WORKDIR /app
 
-ARG VITE_APP_BASE_PATH=/deckofcars/generadorexamenesllm/
+ARG VITE_APP_BASE_PATH=/generadorexamenesllm/
 ARG VITE_API_URL=
 ARG VITE_GOOGLE_CLIENT_ID=
 ENV VITE_APP_BASE_PATH=$VITE_APP_BASE_PATH