Pigeonhole Protocol Decoy traffic for Couriers and Replicas

[david415]

Currently our implementation of the Pigeonhole Protocol is INCOMPLETE AND DOES NOT INCLUDE DECOY TRAFFIC for couriers and storage replicas.

Pigeonhole protocol is described here:
https://arxiv.org/abs/2501.02933

And here:
https://katzenpost.network/docs/specs/pigeonhole/