Chromium rejects authenticated SOCKS5 ('Browser does not support socks5 proxy
authentication'). Add a gost (ginuerzh/gost:2.11.5) 'proxy-relay' sidecar that
listens unauthenticated on socks5://proxy-relay:11080 and forwards to the
authenticated residential upstream (HEALTHCARE_PROXY_UPSTREAM_URL). Workers point
Playwright at the relay via HEALTHCARE_PROXY_URL=socks5://proxy-relay:11080.
env template: split into HEALTHCARE_PROXY_UPSTREAM_URL (authenticated, password
percent-encoded so '#' -> %23) and HEALTHCARE_PROXY_URL (the relay address).
Validated end-to-end on dev: workers Chromium -> proxy-relay -> residential
egress IP 76.228.206.147; NPPES + PECOS both HTTP 200.
a79d6b1906