[Feature] Do not sync when peer consensus version differs

[kaimast]

This PR fixes #3822. It adds a latest_consensus_version to a block response to prevent nodes that did not upgrade from block advancement.

If the peers use different versions of snarkOS, it will either fail to deserialize the block response, or abort when it detects that the version do not match.

Note: This requires upgrading the message version, as the format for BlockResponse changed.

[kaimast]

Strangely, I had to increase the machine size for another CI job. Some recent change caused a lot of our builds to take longer or use up more memory.

[vicsn]

Core logic LGTM! Just a note on backwards compatibility

[ljedrz]

Same point as @vicsn made; we should be able to make it backwards compatible, and only make the new field a hard requirement after a while.

[kaimast]

Thanks for the feedback! I changed the PR to now interpret the start_height of the block request as a version number. For old messages, it is never zero, as nodes do not request the genesis block from other nodes.
For newer messages, it is set to zero for now. In the future, we can use the first byte(s) to encode an actual version.

To make this change simpler, snarkos_node_router_messages now re-export the BlockResponse and BlockRequest types from snarkos_node_bft_events, instead of re-implementing them.

Finally, I needed to make changes to the prop tests for these two message types because they didn't actually generate valid block requests or responses. For example, it picked two random numbers as start and end height, so that the ranges could be invalid. The number of blocks in the response also was not guaranteed to be equal to the size of the request range.

[ljedrz]

Left some nits, but nothing blocking; LGTM 👌.

[vicsn]

Thx! We're almsot there!

[kaimast]

I tested this finally, and you will get an output like the following starting at consensus V12 for nodes that have not upgraded:

2025-10-24T00:19:22.875901Z  WARN snarkvm_utilities::errors: Failed to insert block response — The peer did not send a consensus version
2025-10-24T00:19:22.875950Z  WARN snarkos_node::client::router: Failed to process inbound message from '127.0.0.1:4130' - Peer '127.0.0.1:4130' sent an invalid block response

Before merging/approving: take a look at the most recent change in ddb841b, which ensures messages are always rejected if the local consensus version would be greater than 12.
I believe this is the behavior we want but please double check.

[vicsn]

@kaimast thank you, this is the behaviour we want:

• before V12, old and new nodes can sync from each other
• after V12 old and new nodes can't sync from each other anymore due to the serialization mismatch

Please confirm

[kaimast]

@kaimast thank you, this is the behaviour we want:

* before V12, old and new nodes can sync from each other

* after V12 old and new nodes can't sync from each other anymore due to the serialization mismatch

Please confirm

Yes. That's the behavior.