chore: applied feedback from merge request

Removed all the DOM manipulations and created a utils file so npx eslint
is happy.
Also changed the tests to test the new version of the code.

ref: N25B-189

src/utils/SaveLoad.ts

@@ -0,0 +1,19 @@
+import {type Edge, type Node } from "@xyflow/react";
+
+export type SavedProject = {
+  name: string;
+  savedASavedProject: string; // ISO timestamp
+  nodes: Node[];
+  edges: Edge[];
+};
+
+// Creates a JSON Blob containing the current visual program (nodes + edges)
+export function makeProjectBlob(name: string, nodes: Node[], edges: Edge[]): Blob {
+  const payload = {
+    name,
+    savedAt: new Date().toISOString(),
+    nodes,
+    edges,
+  };
+  return new Blob([JSON.stringify(payload, null, 2)], { type: "application/json" });
+}