Backoff now covers all dial-phase errors (refused, timeout, DNS), TLS
handshake failures, and 5xx responses with replayable bodies; streamed
POSTs are never replayed to avoid duplicate work. First retry of an
episode logs at WARN, subsequent attempts at INFO.
LOGLEVEL (LOG_LEVEL kept as alias) now defaults to warn: startup logs
version plus every setting; INFO adds one line per incoming request and
per response with status/duration, ANSI-colored in text mode (bypasses
slog's escaping so colors render in docker compose logs); NO_COLOR or
LOG_FORMAT=json disables colors.
A refused dial (service down/restarting) is retried with a wait that
doubles from BACKOFF_INITIAL (1s) up to BACKOFF_MAX (60s) until the
upstream answers or the client disconnects. Handles the Windows WSA
errno (10061) as well as POSIX ECONNREFUSED. compose.yaml.example now
uses host.docker.internal like the working local deployment.
mram