WIP: Version-portable protos

[mwaskom]

Describe your changes

TK TK TK — need a PR so I can hack on the actions workflow changes

Backward/forward compatibility checks

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Check these boxes or delete any item (or this section) if not relevant for this PR.

• [ ] Client+Server: this change is compatible with old servers
• [ ] Client forward compatibility: this change ensures client can accept data intended for later versions of itself

Note on protobuf: protobuf message changes in one place may have impact to multiple entities (client, server, worker, database). See points above.

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