remove dev dependencies from development containers

frontend/Dockerfile

@@ -7,7 +7,7 @@ WORKDIR /app/frontend
 COPY frontend/package*.json ./
 
 # Install dependencies
-RUN npm ci
+RUN npm ci && npm cache clean --force
 
 # Copy source code and config files
 COPY frontend/ ./
@@ -25,9 +25,6 @@ RUN npm run build
 # Production stage
 FROM nginx:alpine
 
-# Install envsubst (gettext) so we can template nginx config at runtime
-RUN apk add --no-cache gettext
-
 # Copy nginx config template (will be processed at runtime)
 COPY frontend/nginx.conf.template /etc/nginx/nginx.conf.template
 

frontend/docker-entrypoint.sh

@@ -7,9 +7,9 @@ export BACKEND_URL="${BACKEND_URL:-backend:8000}"
 
 echo "Configuring nginx with BACKEND_URL: ${BACKEND_URL}"
 
-# Substitute environment variables in nginx config template
-# Only substitute BACKEND_URL, preserve nginx variables like $http_upgrade
-envsubst '${BACKEND_URL}' < /etc/nginx/nginx.conf.template > /etc/nginx/nginx.conf
+# Replace only our custom placeholder and preserve nginx runtime vars like $http_upgrade
+ESCAPED_BACKEND_URL=$(printf '%s\n' "$BACKEND_URL" | sed 's/[\/&]/\\&/g')
+sed "s/__BACKEND_URL__/${ESCAPED_BACKEND_URL}/g" /etc/nginx/nginx.conf.template > /etc/nginx/nginx.conf
 
 # Validate the generated nginx configuration before starting
 echo "Validating nginx configuration..."

frontend/nginx.conf.template

@@ -24,7 +24,7 @@ http {
         # API and WebSocket proxy to backend
         # BACKEND_URL is substituted at container startup (default: backend:8000)
         location /api/ {
-            proxy_pass http://${BACKEND_URL}/;
+            proxy_pass http://__BACKEND_URL__/;
             proxy_http_version 1.1;
             proxy_set_header Upgrade $http_upgrade;
             proxy_set_header Connection 'upgrade';
@@ -49,7 +49,7 @@ http {
 
         # WebSocket proxy for Socket.IO
         location /socket.io/ {
-            proxy_pass http://${BACKEND_URL}/socket.io/;
+            proxy_pass http://__BACKEND_URL__/socket.io/;
             proxy_http_version 1.1;
             proxy_set_header Upgrade $http_upgrade;
             proxy_set_header Connection 'upgrade';