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

roles/web-app-chess/README.md

@@ -1,2 +1,25 @@
-# Todo 
-- Implement https://joinbookwyrm.com/de/
+# web-app-chess
+
+## Description
+
+**castling.club** is a federated chess server built on the ActivityPub protocol.  
+It provides an open and decentralized way to play chess online, where games and moves are visible across the Fediverse.
+
+## Overview
+
+Instead of relying on closed platforms, castling.club uses an arbiter actor (“the King”) to validate moves and mediate matches.  
+This ensures fair play, federation with platforms like Mastodon or Friendica, and community visibility of ongoing games.  
+The service runs as a lightweight Node.js app backed by PostgreSQL.
+
+## Features
+
+- **Federated Chess Matches:** Challenge and play with others across the Fediverse.  
+- **Rule Enforcement:** The arbiter validates each move for correctness.  
+- **Open Identities:** Use your existing Fediverse account; no new silo account needed.  
+- **Game Visibility:** Matches and moves can appear in social timelines.  
+- **Lightweight Service:** Built with Node.js and PostgreSQL for efficiency.  
+
+## Further Resources
+
+- [castling.club GitHub Repository](https://github.com/stephank/castling.club)  
+- [ActivityPub Specification (W3C)](https://www.w3.org/TR/activitypub/)