new build structure

frontend/Dockerfile

@@ -0,0 +1,24 @@
+# frontend/Dockerfile
+FROM node:20-alpine AS build
+WORKDIR /app
+COPY package*.json ./
+RUN npm install
+COPY . .
+# Wir setzen die API-URL auf den relativen Pfad, da Frontend und Backend 
+# jetzt unter der gleichen Domain laufen werden!
+ENV VITE_API_URL="" 
+RUN npm run build
+
+FROM nginx:alpine
+COPY --from=build /app/dist /usr/share/nginx/html
+# Standard Nginx-Config für Single Page Applications (React/Vite)
+RUN echo 'server { \
+    listen 80; \
+    location / { \
+        root /usr/share/nginx/html; \
+        index index.html; \
+        try_files $uri $uri/ /index.html; \
+    } \
+}' > /etc/nginx/conf.d/default.conf
+EXPOSE 80
+CMD ["nginx", "-g", "daemon off;"]