Sanctum for developers: LST swap API, Gateway transaction delivery, and on-chain programs

Sanctum exposes two distinct developer surfaces: the LST swap API (ExactIn/ExactOut routes across 200+ LSTs via Ironforge) and Sanctum Gateway (JSON-RPC transaction delivery aggregator routing through Jito, SWQoS RPCs, Helius, Nozomi, and more). Here is how to use both.