This is doing to many things at once. You should break this up, and, as you do so, you'll discover that there are various holes in some parts. This is just going to take forever to get all the parts right if they all prevent each other from moving.

add a functional test

Remove extra comment, mark mocks as generated

You'll keep shuffling things around until you ask yourself the questions "What does the initialization?" "What does fetch the config?" "What does verify the validity of the different parameters?" and so on. Once you got the answers to these question, you need to apply them consistently.

Add also a bloom filter for recent rejects, to avoid checking bad proof multiple time.

address review: check the proof before initializing a Processor, rename Processor::Init -> Processor::MakeProcessor, make it return a Processor * or a nullptr (if the proof verification failed), call InitError direcly in processor.cpp to avoid error messages as out parameters,

use a factory method that return possible error, restore the previous behavior of InitError instead of LogPrintf

remove the need to check avaproof in init.cpp by moving the logging into the Processor's constructor.

You need to find what the right API for initialization is. Fixing the current API is mostly motion not progress. If you initialized where thing should be initialized, you wouldn't need to access the proof here now (maybe later, but later is later) and therefore, you wouldn't need to figure out what is the right API to access the proof.

rebase onto D9394. This solves the issue of getLocalProof making an unnecessary copy, or hasLocalProof returning a boolean.

rebase onto D9394. This puts the getProof -> getLocalProof renaming in it's own diff

still missing tests

fix nits and don't verify the proof twice

fix build failure : I forgot to change init.cpp when renaming getLocalProof

implement addProof, store fully valid proofs as new peers, store proofs with missing UTXOs as orphanProofs, make is a simple map (we can always change back it to a multi-index container if needed), replace hasProof with a getProof method that return a nullptr if we don't have it, rename previous Processor::getProof to Processor::getLocalProof