Signal handling fixes:
- SignalListener: add SIGHUP/SIGTERM handling for both Swoole
and Workerman drivers in master and worker processes
- Prevent 100% CPU when IDE terminal is closed by ensuring
graceful shutdown on terminal hangup
PHP version support:
- Widen PHP constraint to 8.3, 8.4, 8.5
- Bump doctrine/dbal from ^2.13.1 to ^4.4
- Bump php-cs-fixer to ^3.64, phpstan to ^1.12
- Bump swoole/ide-helper to ^5.0
- Drop phpunit ^8.5 (EOL), keep ^9.0
CI updates:
- actions/checkout@v3 → @v4 (Node.js 20 deprecated)
- Bump static analysis/code style PHP from 8.1 to 8.3
