build(docker): Private mode deployment test successful

Test steps:
bash docker/scripts/generate-config.sh --mode private [--local-ip 192.168.0.113]
bash ./deploy.sh --mode private

Front-end directly inlines NEXT_PUBLIC_API_URL, directly connecting to the backend.
CORS (production) supports comma-separated multiple origins, with localhost and local network IPs included by default.

backend/Dockerfile

@@ -5,9 +5,9 @@ ARG HTTP_PROXY
 ARG HTTPS_PROXY
 ARG NO_PROXY
 
-ENV http_proxy=${HTTP_PROXY} \
-    https_proxy=${HTTPS_PROXY} \
-    no_proxy=${NO_PROXY}
+ENV http_proxy ${HTTP_PROXY} \
+    https_proxy ${HTTPS_PROXY} \
+    no_proxy ${NO_PROXY}
 
 WORKDIR /app
 COPY package*.json ./