fix: Docker build uses host network for proxy access

Build with network:host so npm/curl inside the build container can
directly use the host's proxy (127.0.0.1). Eliminates the need for
BUILD_PROXY and host.docker.internal resolution during build.

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

.env.example

@@ -11,10 +11,7 @@ CODEX_ARCH=arm64       # arm64/x64
 # ── Port ──
 PORT=8080
 
-# ── Docker proxy ──
-# Build-time: proxy for npm install / GitHub downloads inside Docker build.
-# host.docker.internal refers to the Docker host machine.
-# BUILD_PROXY=http://host.docker.internal:7890
-
-# Runtime: proxy for the container to reach chatgpt.com.
+# ── Docker runtime proxy ──
+# The container needs a proxy to reach chatgpt.com.
+# host.docker.internal resolves to the Docker host machine.
 # CONTAINER_PROXY=http://host.docker.internal:7890

Dockerfile

@@ -7,12 +7,6 @@ RUN apt-get update && \
 
 WORKDIR /app
 
-# Optional build-time proxy for npm/GitHub downloads inside RUN commands.
-# Uses custom arg name to avoid BuildKit intercepting HTTP_PROXY for image pulls.
-# Docker daemon's own proxy handles image pulls separately.
-ARG BUILD_PROXY
-ENV http_proxy=${BUILD_PROXY} https_proxy=${BUILD_PROXY}
-
 # Install backend dependencies (postinstall downloads curl-impersonate for Linux)
 COPY package*.json ./
 RUN npm ci
@@ -29,9 +23,6 @@ RUN npx tsc
 # Prune dev dependencies
 RUN npm prune --omit=dev
 
-# Clear build-time proxy from image
-ENV http_proxy= https_proxy=
-
 # Persistent data mount point
 VOLUME /app/data
 

docker-compose.yml

@@ -2,10 +2,8 @@ services:
   codex-proxy:
     build:
       context: .
-      args:
-        # Proxy for RUN commands (npm install, curl downloads).
-        # host.docker.internal resolves to the Docker host's IP.
-        - BUILD_PROXY=${BUILD_PROXY:-}
+      # Use host network during build so npm/curl can reach proxy at 127.0.0.1
+      network: host
     ports:
       - "${PORT:-8080}:8080"
     volumes: