Transfer-context lookup by original_call_sid ran
`redis.keys("transfer:context:*")` and iterated every match — an O(N)
blocking scan on call-control hot paths, duplicated across the ARI
manager and the Twilio/Telnyx conference strategies.
Maintain a `transfer:by_call_sid:{original_call_sid}` -> transfer_id
secondary index, written and cleared alongside the context in
store/remove, and resolve lookups with a direct GET. Route the
Twilio/Telnyx strategies through the manager so the lookup lives in one
place (also dropping per-call ad-hoc Redis connections).
Closes#328
Co-authored-by: shiminshen <16914659+shiminshen@users.noreply.github.com>
Conference-based transfer for Telnyx with a two-step flow:
- transfer_call dials the destination with a per-transfer webhook URL.
- On call.answered, the webhook seeds a conference with the destination's
live call_control_id and publishes DESTINATION_ANSWERED.
- TelnyxConferenceStrategy joins the caller into the conference on
pipeline teardown (EndTaskReason.TRANSFER_CALL).
- On post-answer destination hangup, the webhook hangs up the caller —
Telnyx's create_conference doesn't accept end_conference_on_exit on
the seed leg, so we tear down the bridge ourselves.
TransferContext gains optional workflow_run_id (for webhook→provider
resolution in multi-config orgs) and conference_id (set on answer,
rd by the strategy).
Also fixes the transfer tool's provider lookup to go through
get_telephony_provider_for_run instead of the deprecated org-default
shim, which was returning the wrong provider in multi-config orgs.