ctl upgrade asks the server what it runs, and waits for a node as long as it does

A binary installed by hand made ctl upgrade say this machine already ran
the release and leave the old server running. And a node had 15 seconds
to answer an upgrade the control plane gives five minutes, so a node that
was upgrading stopped the run.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/admin-api.openapi.json

@@ -5416,6 +5416,10 @@
         "type": "object",
         "description": "Summary is the whole fleet in one answer.\n\nA per-node listing is the right tool for four nodes and the wrong one for two hundred: the questions that matter at that size — how full am I, what is broken, what is holding cards it is not using — are aggregates, and reading them off a long table is a chore that gets skipped. Everything here is derived from the same state the tables show, so it can never disagree with them; it is a different question asked of the same facts.",
         "properties": {
+          "version": {
+            "type": "string",
+            "description": "Version is the release the answering control plane runs: not the binary on its disk, which a manual install changes underneath it."
+          },
           "nodes": {
             "$ref": "#/components/schemas/NodeTotals"
           },