QUICKSTART gains a Twilio Media Streams section: env-var table for the four
RUTSTER_TWILIO_* vars, the run-with-twilio-live command, the point-Twilio-
at-rutster webhook/TwiML walkthrough, + the outbound-call curl example. The
/v1/trunk routes' auth-deferral (slice 6) is flagged. A 'what's different
from WebRTC' note explains the architectural reuse -- the reflex stack is
ingress-agnostic (Reflex<TapAudioPipe> + LocalVadReflex REUSED from slice-4).
README's spearhead status is corrected + extended: slices 1-4 are merged to
main (the prior status stalled at '1-3 merged, slice-4 active' -- stale);
4.5 (sim/benchmark, ADR-0010) + step 5 (PSTN via rented transport, ADR-0007)
are the active build targets. ADR-0007 honored: rutster parses zero SIP bytes.
T9 of slice-5.
Signed-off-by: Aaron D. Lee <himself@adlee.work>