RSS stuck for single-node non-gimlet deployment due to missing zpool?

I don't quite understand what's going on here, but I want to teardown this deployment and try standing up omicron again so I'm not blocked, so I'm dumping some state for now.

I deployed omicron on dunkin, a lab machine. The stack never quite came up, with this message repeatedly showing up from sled agent:

    file = sled-agent/src/rack_setup/service.rs:627
18:07:10.200Z INFO SledAgent (RSS): Failed to handoff to nexus: Error Response: status: 404 Not Found; headers: {"content-type": "application/json", "x-request-id": "09f78537-e5f6-4452-82d2-280e443e9e69", "content-length": "174", "date": "Wed, 04 Oct 2023 18:07:09 GMT"}; value: Error { error_code: Some("ObjectNotFound"), message: "not found: zpool with id \"616b26df-e62a-4c68-b506-f4a923d8aaf7\"", request_id: "09f78537-e5f6-4452-82d2-280e443e9e69" }

That zpool exists on this system:

$ zpool status oxp_616b26df-e62a-4c68-b506-f4a923d8aaf7
  pool: oxp_616b26df-e62a-4c68-b506-f4a923d8aaf7
 state: ONLINE
  scan: none requested
config:

        NAME                                                                           STATE     READ WRITE CKSUM
        oxp_616b26df-e62a-4c68-b506-f4a923d8aaf7                                       ONLINE       0     0     0
          /home/jordan/omicron/tools/../oxp_616b26df-e62a-4c68-b506-f4a923d8aaf7.vdev  ONLINE       0     0     0

errors: No known data errors

I looked for evidence of this request on the 3 nexuses in my deployment, and couldn't find a matching request (I looked for request ID and also just grepped for that zpool uuid). That log line comes from here:

https://github.com/oxidecomputer/omicron/blob/a9104a0786f437e38d4945dd77470bc8fd4f974c/sled-agent/src/rack_setup/service.rs#L608-L635

Start at sled-agent/src/rack_setup/service.rs around lines 608-635 and trace the RSS handoff to Nexus. Reproduce or inspect the single-node non-gimlet deployment state, comparing the zpool UUID reported by sled agent with the zpool visible to Nexus. Done should identify why the existing zpool is reported as missing and document a verified resolution.