Implement auto-generation of ecosystem.config.js and improve container setup

- Add automatic ecosystem.config.js generation from package.json
- Create app directory automatically if missing
- Copy simple-website example when app directory is empty
- Remove redundant default app files from configs/
- Add HAProxy support with proper real IP forwarding
- Configure nginx to trust proxy headers from private networks
- Simplify entrypoint logic - always use /home/$user/app

This makes the container more user-friendly by eliminating the need for
manual PM2 configuration and ensuring the server always has a working app.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

Dockerfile

@@ -5,7 +5,8 @@ ARG NODEVER=20
 RUN dnf install -y \
       https://dl.fedoraproject.org/pub/epel/epel-release-latest-9.noarch.rpm && \
     dnf update -y && \
-    dnf install -y wget procps cronie iproute nginx openssl && \
+    dnf install -y wget procps cronie iproute nginx openssl git microdnf make gcc gcc-c++ && \
+    yum groupinstall 'Development Tools' && \
     dnf clean all && \
     rm -rf /var/cache/dnf /usr/share/doc /usr/share/man /usr/share/locale/* \
            /var/cache/yum /tmp/* /var/tmp/*
@@ -25,11 +26,11 @@ RUN npm install -g pm2@latest --production && \
     npm cache clean --force && \
     rm -rf /tmp/*
 
-# Copy configs and web files
+# Copy nginx config
 COPY ./configs/nginx.conf /etc/nginx/nginx.conf
-COPY ./configs/index.js /var/www/html/
-COPY ./configs/package.json /var/www/html/
-COPY ./configs/ecosystem.config.js /var/www/html/
+
+# Copy examples directory for default app fallback
+COPY ./examples/ /examples/
 
 # Set up cron job for log rotation
 RUN echo "15 */12 * * * root /scripts/log-rotate.sh" >> /etc/crontab