Preserve dataflow layout across SQL edits

webui/scripts/test-dataflow-page-structure.mjs

@@ -27,6 +27,14 @@ const checks = [
       && !css.includes(".dataflow-alerts"),
     "central floating dismissible alerts"
   ],
+  [
+    !css.includes(".dataflow-results-toolbar .segmented-control"),
+    "ungapped shared results segmented control"
+  ],
+  [
+    page.includes("response.graph.nodes.some((node) => node.id === selectedNodeId)"),
+    "selected node preservation across SQL roundtrips"
+  ],
   [page.includes("useUnsavedDraftGuard"), "unsaved-change guard"],
   [canvas.includes("application/x-govoplan-dataflow-node"), "palette drop handling"],
   [canvas.includes("isValidConnection"), "edge validation"],