BasharMithan/VerChain ? reverse-engineered prompt

Build me a Python app for privacy first credential verification using a simple blockchain style peer to peer network.

I want users, issuers, and a verifier to be able to create identities, issue a credential, turn that into a compact CHID reference, and store only that reference on the chain instead of any personal data. Then the verifier should be able to query the network, find the matching CHID, and check ownership without exposing the real credential details.

Please include the networking pieces for peers to start, connect, broadcast, and send messages, plus an event driven callback flow so the app reacts when nodes connect, disconnect, or receive data. Add the basic models for user, authority, credential, block, CHID, and a query flow, and make it easy to run a small local demo from Python.

Keep it clean and readable, and if you need current docs for anything in the standard library or blockchain related approach, look them up online.