Update SSL certificate, NGINX configuration, and pgAdmin setup

- Updated the SSL certificate for yuri.phx-erp.de with a new signed certificate.
- Added a new NGINX configuration file for pgAdmin reverse proxy under the subpath /pgadmin4.
- Enhanced the main NGINX configuration with improved logging, security headers, and real IP handling.
- Implemented health check endpoints for both system and worker services with IP whitelisting.
- Created a new entrypoint script for pgAdmin to manage .pgpass and servers.json configuration.
- Removed the redis.conf file and commented out Redis session caching in the configuration.

nginx/includes/pgadmin.conf

@@ -0,0 +1,15 @@
+# pgAdmin reverse proxy (under subpath)
+location /pgadmin4 {
+    proxy_pass http://pgAdmin4_Ui/;
+    proxy_set_header X-Script-Name /pgadmin4;
+    proxy_set_header X-Scheme $scheme;
+    proxy_set_header X-Forwarded-Proto $forwarded_proto;
+    # Include headers for proxying
+    proxy_set_header Host $host;
+    proxy_set_header X-Real-IP $remote_addr;
+    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+    proxy_set_header X-Forwarded-Host $host;
+    proxy_set_header X-Forwarded-Proto $forwarded_proto;
+    # End of headers
+    proxy_redirect off;
+}