remove admin web panel (LichessWebView) from the project

Unused component that also carried several security issues (default
admin credentials, hardcoded Flask secret key, debug mode, plaintext
passwords). Cleaned up compose files, CI/CD pipeline, and docs
accordingly; also dropped the stale IS_PROD config docs in favor of
the current .env-based setup.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

start.sh

@@ -54,7 +54,6 @@ echo "✅ Все сервисы запущены!"
 echo ""
 echo "🌐 Доступные сервисы:"
 echo "   - API документация: http://localhost:8002/docs"
-echo "   - Веб-интерфейс: http://localhost:5000"
 echo ""
 echo "📋 Для просмотра логов используйте:"
 echo "   ${COMPOSE_CMD_DISPLAY} logs -f"