If there are multiple telephony configurations, the form number should be initialized from the campaigns given telephonic configuration rather than the organization default telephonic configuration.
For outbound calls, the caller phone is stored as "phone_number" in
initial_context. For inbound calls, it is stored as "caller_number".
The usage log extraction only checked "phone_number", so inbound
caller numbers were never surfaced.
Add a fallback to also check "caller_number" when "phone_number" is absent.
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>