v5.0.1

• Remove silent catch in buildPayload() so exceptions propagate to
  onShutdown(), eliminating the [] return path that caused the ingress
  unmarshal error
• onShutdown() now returns early on any failure instead of sending a
  malformed error payload to Treblle
• Replace mb_trim() (PHP 8.4+) with trim() in response header parsing,
  fixing a fatal error on PHP 8.2/8.3
• Remove mb_str_functions Pint rule which was silently re-introducing
  PHP 8.4-only functions on every format run
• Guard getallheaders() against false return with ?: []
• Add null coalescence to HTTP_HOST and REQUEST_URI in URL construction
• Updated README