feat(web-app-chess): add castling.club role with ports, networks, and build setup

- Added network subnet (192.168.103.192/28) and port 8050 for web-app-chess
- Replaced stub README with usability-focused description of castling.club
- Implemented config, vars, meta, and tasks for web-app-chess
- Added Dockerfile, docker-compose.yml, env, and docker-entrypoint.sh templates
- Integrated entrypoint asset placement
- Updated meta to reflect usability and software features

Ref: https://chatgpt.com/share/68b6c65a-3de8-800f-86b2-a110920cd50e

group_vars/all/09_networks.yml

@@ -96,6 +96,8 @@ defaults_networks:
       subnet: 192.168.103.160/28
     web-svc-logout:
       subnet: 192.168.103.176/28
+    web-app-chess:
+      subnet: 192.168.103.192/28
 
     # /24 Networks / 254 Usable Clients
     web-app-bigbluebutton:

group_vars/all/09_ports.yml

@@ -71,6 +71,7 @@ ports:
       web-app-mig: 8047
       web-svc-logout: 8048
       web-app-bookwyrm: 8049
+      web-app-chess: 8050
       web-app-bigbluebutton: 48087    # This port is predefined by bbb. @todo Try to change this to a 8XXX port
   public:
     # The following ports should be changed to 22 on the subdomain via stream mapping