Add smart caching for Hiro's RPC Endpoints

[saralab]

Proposing an intelligent caching layer for our Hiro RPC endpoints that sit on top of the Stacks node. This isn’t just about cutting down response times and reducing load on the node (though it will do both really well). It’s about setting us up to scale API usage smoothly, improve developer experience, and make our infrastructure more reliable. The caching layer will still respect data consistency and freshness, so we get the speed gains without compromising trust.

Right now, our RPC infra runs into some real bottlenecks:Latency, scaling limits, handling spiky traffic . Some of these have led to builders running their own proxy nodes.

More details on the Notion doc