[propolis] make API versioned

[sunshowers]

Last part of oxidecomputer/omicron#8922 for Propolis.

[sunshowers]

looking at the migration_smoke test for example, the server is returning a 500: https://buildomat.eng.oxide.computer/wg/0/artefact/01K717KJSAFFZEZRRCPGK10RJ5/bvmawp89NoBGXZ5jEjKUtQkXmSjjd2pTVbq79DYSSWuQxW0x/01K717KWC9JNT7MDN1FB8QG55C/01K719297J2K1SXCT1GQNJCXXY/phd-runner.log?format=x-bunyan#L88.

downloading the log file tarball, within migration_smoke.stdout.log, I'm seeing:

{"msg":"failed to determine request API version","v":0,"name":"propolis-server","level":50,"time":"2025-10-08T06:38:57.426243649Z","hostname":"buskin","pid":868,"uri":"/instance/migrate/0dd308a4-bf7d-4bee-b8f6-c8bee8e9248f/start","method":"GET","req_id":"3e08a376-c7c1-4385-86d7-6493b7a4e76f","remote_addr":"127.0.0.1:57147","local_addr":"127.0.0.1:9000","error":"HttpError { status_code: 400, error_code: None, external_message: \"missing expected header \\\"api-version\\\"\", internal_message: \"missing expected header \\\"api-version\\\"\", headers: None }"}

That looks like the phd-runner is somehow using a Progenitor version < 0.10.0 (ie before the first version that sent the api-version header). But the Cargo.lock doesn't have any references to Progenitor 0.9 at all. Could the phd runner be using some kind of binary that needs to be rebuilt?

[sunshowers]

Ah, so the issue is that this code is constructing its own client which of course won't include the API header.

propolis/bin/propolis-server/src/lib/migrate/destination.rs

Lines 82 to 93 in 6b161e8

	// Build upgrade request to the source instance
	// (we do this by hand because it's hidden from the OpenAPI spec)
	// TODO(#165): https (wss)
	// TODO: We need to make sure the src_addr is a valid target
	let src_migrate_url = format!(
	"ws://{}/instance/migrate/{}/start",
	migrate_info.src_addr, migration_id,
	);
	info!(log, "Begin migration"; "src_migrate_url" => &src_migrate_url);
	let (mut conn, _) =
	tokio_tungstenite::connect_async(src_migrate_url).await?;

Going to dig into what to do here.

[sunshowers]

So this is propolis-server instances making direct requests to other propolis-server instances to start migrations. I'm not sure how this would work in the context of self-service update, where the propolis-server instances might be on different versions.

There are two parts to this:

1. The InstanceMigrateStartRequest path params, which seems to just have the migration ID.
2. The actual migration protocol (though there seems to be protocol negotiation built into that part of migration, so maybe version skew isn't an issue there)

[sunshowers]

We addressed the above concern in #957.

[sunshowers]

Ah so the migrate-from-base test will fail until the api-version header is passed in. So I guess I'll need to split that change into its own PR.