Control-plane requests follow the lease but take no slot and write no row

Implemented-By: OpenCode session (model recorded in docs/implementer-log.md)

internal/proxy/proxy_test.go

@@ -257,7 +257,9 @@ func TestV0BehaviourStillHolds(t *testing.T) {
 	}{
 		{http.MethodGet, "/", 400, "missing route"},
 		{http.MethodGet, "/nope/v1/models", 404, "unknown route"},
-		{http.MethodGet, "/r/slots", 404, "not found"},
+		// v2.3: /slots itself is proxied (a control-plane path); its per-slot actions are not.
+		{http.MethodGet, "/r/slots/0", 404, "not found"},
+		{http.MethodGet, "/r/metrics", 404, "not found"},
 		{http.MethodGet, "/r/_crossbar/hosts", 404, "not found"},
 	} {
 		req, _ := http.NewRequest(tc.method, r.front.URL+tc.path, nil)