feat(cli): add ctrld diag for provisioning support

internal/controld/reachability_test.go

@@ -0,0 +1,14 @@
+package controld
+
+import (
+	"context"
+	"testing"
+)
+
+func TestProbeReachabilityRespectsCancelledContext(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+	if err := ProbeReachability(ctx, false); err == nil {
+		t.Error("expected an error for an already-cancelled context")
+	}
+}