TravelBooking_v1.4

Authoritative two-phase flight booking workflow (Search → Book) using AgentGatewayCall (logic manifest 4523728E, blueprint E2B027F5). Collects search inputs, presents real returned options, collects passenger/contact details, books, and returns booking reference and credits deducted. Enforces HARD_THREAD_ISOLATION and APH-01 compliance, with 180s cadence for follow-ups when awaiting user input.