feat(ami): M7 CP3 — AMI Originate waits for answer before running the app

[ryanmurf]

M7 CP3 (flagship) — AMI Originate waits for answer before running the app

handle_originate ran the dialplan app/exten immediately after driver.call()
put the INVITE on the wire — before the far end answered. For a PJSIP origination
the app executed (and the leg usually tore down) before the carrier's 200 OK,
orphaning a delayed answer.

Fix

For a PJSIP Originate, after the INVITE is sent the handler waits (up to the
Originate Timeout) for the store channel to reach Up — set by the 2xx answer
path — before running the app. On rejection/hangup/timeout it abandons the leg
(CANCEL a still-pending INVITE via cancel_or_bye_outbound_leg) without
running the app and reports OriginateResponse: Failure.

Flagship receiver-side proof (isolated offline-carrier harness)

tests/cp3-originate-wait/run.sh — the carrier DELAYS its 200 and tags every
captured datagram phase=pre (before it sent the 200) or phase=post:

PRE-ANSWER SILENCE (only INVITE before the 200, no ACK/BYE/CANCEL/RTP): PASS
POST-ANSWER RUN   (answer ACKed + app BYE after the 200):              PASS
RTP datagrams pre-answer (must be 0):  0

INVITE phase=pre  ... cseq=1 INVITE rel=0.765
SENT-200          ... rel=2.766
ACK    phase=post ... cseq=1 ACK    rel=2.766
BYE    phase=post ... cseq=2 BYE    rel=3.771

Nothing but the INVITE reaches the carrier in the 2-second pre-answer window; the
ACK and the app-driven BYE arrive only after the 200.

Captured RED

Disable the wait (app runs immediately):

PRE-ANSWER SILENCE ... : PASS
POST-ANSWER RUN    ... : FAIL
INVITE phase=pre ... rel=0.776
SENT-200         ... rel=2.776   <- no ACK, no BYE ever follow

The delayed 200 is orphaned (never ACKed) because the app ran and abandoned the
leg before answer → POST-ANSWER assertion RED.

cargo test --workspace --exclude pjsip-shim + clippy … -D warnings green.
Rust 1.97.0. (CP3 is an end-to-end Originate-timing behavior; the harness is its
RED-capable proof.)