The hang appears to be in the cloning phase before we even create the index, so it is a different issue from: SERVER-113365. (Example patch). Note that this issue does not appear when resharding is run in a suite where shards have one node. 

I noticed this repeatedly getting logged on the shard nodes: 

[j6:s1:prim] | 2026-01-21T21:40:20.548+00:00 D2 REPL_HB  11222004 [S] [Disagg-3] "Encountered error when initializing heartbeat response","attr":
{
    requestId: 2981,
    target: "localhost:21515",
    error: {
        code: 4,
        codeName: "NoSuchKey",
        errmsg: "Missing expected field \"durableOpTime\""
    }
}

Not sure if that's related to the issue or a side effect.