fix: change appuser to uid:gid 1000:1000 for security

- Use standard user uid:gid 1000:1000 instead of 100:101 (postfix:crontab)
- Add user override in docker-compose.yml to ensure consistent uid:gid
- Prevents .env files from having system service account permissions
- Addresses critical security concern in issue #109

Dockerfile

@@ -28,8 +28,8 @@ FROM node:18-alpine
 
 WORKDIR /usr/src/app
 
-# Create a non-root user and group
-RUN addgroup -S appgroup && adduser -S appuser -G appgroup
+# Create a non-root user and group with uid:gid 1000:1000 (standard user)
+RUN addgroup -g 1000 appgroup && adduser -u 1000 -G appgroup -s /bin/sh -D appuser
 
 # Copy necessary files from builder stage
 # Copy node_modules first (can be large)

docker-compose.yml

@@ -7,6 +7,7 @@ services:
     # image: rcourtman/pulse:latest # Use the pre-built image from Docker Hub
     container_name: pulse
     restart: unless-stopped
+    user: "1000:1000"  # Run as standard user, not system service accounts
     ports:
       # Map container port 7655 to host port 7655
       # You can change the host port (left side) if 7655 is already in use on your host