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/templates/docker-entrypoint.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+APP_KEY_FILE="${APP_KEY_FILE:-/app/data/{{ CHESS_KEY_FILENAME }}}"
+APP_KEY_PUB="${APP_KEY_FILE}.pub"
+
+# 1) Generate signing key pair if missing
+if [[ ! -f "${APP_KEY_FILE}" || ! -f "${APP_KEY_PUB}" ]]; then
+  echo "[chess] generating RSA signing key pair at ${APP_KEY_FILE}"
+  /app/tools/gen-signing-key.sh "${APP_KEY_FILE}"
+fi
+
+# 2) Wait for PostgreSQL if env is provided
+if [[ -n "${PGHOST:-}" ]]; then
+  echo "[chess] waiting for PostgreSQL at ${PGHOST}:${PGPORT:-5432}..."
+  until pg_isready -h "${PGHOST}" -p "${PGPORT:-5432}" -U "${PGUSER:-postgres}" >/dev/null 2>&1; do
+    sleep 1
+  done
+fi
+
+# 3) Run migrations (idempotent)
+echo "[chess] running migrations"
+yarn migrate up
+
+# 4) Start app
+echo "[chess] starting server on port ${PORT:-5080}"
+exec yarn start