The probe now reads WEB_PORT from the server's .env — the same file compose reads —
and builds the health URL from it, falling back to 8001 (compose's own default) when
it is unset. No more passing HEALTH_URL by hand when the published port changes.
Parsed the way compose parses it: last assignment wins, surrounding quotes and
inline whitespace stripped, commented lines ignored.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>