The operator documentation surface. Lists every RUTSTER_* var with its
default + the slice that introduced it + the fail-fast behavior. Includes:
* Artifact-level (this slice): RUTSTER_DOMAIN, RUTSTER_ACME_EMAIL,
RUTSTER_LOCAL_CERTS (CI override).
* FOB engine (slice-5 + plan-A): RUTSTER_HTTP_BIND,
RUTSTER_DRAIN_DEADLINE_SECS=600 (paired with compose stop_grace_period
660s per spec §2.2 — grace exceeds drain), RUTSTER_MAX_SESSIONS,
RUTSTER_MEDIA_BIND_IP/ADVERTISED_IP/PORT_RANGE, RUTSTER_WS_PING_SECS,
RUTSTER_TRUSTED_PROXIES.
* Trunk (slice-5): the four RUTSTER_TWILIO_* (all-or-none — config.rs
twilio_credentials rejects partial).
* Brain (slice-2/3): RUTSTER_TAP_URL (loopback-only until step 6).
* Future var stubs: RUTSTER_TLS_CERT/KEY (slice C), RUTSTER_METRICS_BIND
(slice D), RUTSTER_VALKEY_URL (slice E) — commented out with a pointer
to the sibling plan.
Bundled-binary licenses noted in the header comment (Caddy Apache-2.0,
valkey BSD-3, s6-overlay ISC, libopus0 BSD-3 — aggregation-clean vs
GPL-3 per ADR-0004); seeds the future cargo-deny-adjacent image license
scan (spec §6.1, out of scope for this slice).
Registry namespace git.adlee.work/alee/rutster-* + the 'if your Gitea
registry uses a different owner segment, replace alee throughout' note.
Signed-off-by: Aaron D. Lee <himself@adlee.work>
