swarm-ui: a todo switched from clear to upsert drops its prefix flag

frontend/packages/swarm-ui/src/pages/notifications/FlowDraft.ts

@@ -200,6 +200,20 @@ export function reparent(
   };
 }
 
+// A todo with its op switched. A clear carries no text, and only a clear may
+// be a prefix, so each is reset where the new op has no place for it.
+export function withOp(
+  node: Extract<FlowNode, { kind: "todo" }>,
+  op: "upsert" | "clear",
+): Extract<FlowNode, { kind: "todo" }> {
+  return {
+    ...node,
+    op,
+    text: op === "clear" ? "" : node.text,
+    prefix: op === "clear" ? node.prefix : false,
+  };
+}
+
 // The node with `next.id` swapped for `next`. A node keeps its place and its
 // kind-class: the source stays the source, and nothing with children becomes
 // a todo.