fix(node-editor): auto-layout on load + viewport to top-left

Run auto-layout automatically when a workflow is loaded so nodes are
tidily positioned instead of scattered at persisted positions. Position
the viewport at (0,0) with zoom 1 so the laid-out nodes are visible in
the top-left corner.

- workflow-auto-layout.ts: change ORIGIN_X/Y from 40 to 0
- WorkflowNodeEditor.tsx: apply autoLayout on load, setViewport to top-left
- WorkflowNodeEditor.test.tsx: update test to verify layout runs on load

packages/dashboard/app/components/WorkflowNodeEditor.tsx

@@ -9,6 +9,7 @@ import {
   MiniMap,
   useNodesState,
   useEdgesState,
+  useReactFlow,
   type Connection,
   type Node as FlowNode,
   type Edge as FlowEdge,
@@ -750,6 +751,8 @@ function InnerEditor({
       // localStorage unavailable (private mode / SSR): non-fatal.
     }
   }, [settingsCollapsed]);
+  // React Flow instance for programmatic viewport control (auto-layout on load).
+  const { setViewport } = useReactFlow();
   // Wrapper around <ReactFlow> so keyboard deletion can return focus to the
   // canvas container (R6) instead of leaving it on a now-removed node.
   const canvasRef = useRef<HTMLDivElement>(null);
@@ -1070,11 +1073,15 @@ function InnerEditor({
       return;
     }
     const flow = irToFlow(activeWorkflow);
-    setNodes(flow.nodes);
-    setEdges(flow.edges);
     const loadedColumns = columnsOf(activeWorkflow);
     const loadedFields = fieldsOf(activeWorkflow);
     const loadedSettings = settingsOf(activeWorkflow);
+    // Auto-layout on load: compute tidy positions and apply them before the
+    // first render so nodes are visible in the top-left viewport.
+    const layoutPositions = autoLayout(flow.nodes, flow.edges, loadedColumns);
+    const laidOutNodes = applyAutoLayout(flow.nodes, layoutPositions);
+    setNodes(laidOutNodes);
+    setEdges(flow.edges);
     setColumns(loadedColumns);
     setFields(loadedFields);
     setSettings(loadedSettings);
@@ -1087,7 +1094,7 @@ function InnerEditor({
     loadedSnapshotRef.current = serializeGraph(
       activeWorkflow.name,
       activeWorkflow.description ?? "",
-      flow.nodes,
+      laidOutNodes,
       flow.edges,
       loadedColumns,
       loadedFields,
@@ -1096,6 +1103,8 @@ function InnerEditor({
     setSelectedNodeId(null);
     setSelectedEdgeId(null);
     setValidationError(null);
+    // Position viewport at top-left so the laid-out nodes are visible.
+    setViewport({ x: 0, y: 0, zoom: 1 }, { duration: 0 });
     // Honor a pending AI interpreter-only flag exactly once for the workflow it
     // just activated; otherwise the banner clears on load (U10/R11).
     if (pendingInterpreterOnlyRef.current) {
@@ -1104,7 +1113,7 @@ function InnerEditor({
     } else {
       setInterpreterOnly(false);
     }
-  }, [activeWorkflow, setNodes, setEdges]);
+  }, [activeWorkflow, setNodes, setEdges, setViewport]);
 
   // `?panel=settings` deep link (U6/U9 redirect stubs): once the active workflow
   // has loaded, scroll the settings panel into view. Runs once per editor open.

packages/dashboard/app/components/__tests__/WorkflowNodeEditor.test.tsx

@@ -427,7 +427,7 @@ describe("WorkflowNodeEditor — U5 auto-layout", () => {
     expect(screen.queryByTestId("wf-auto-layout")).not.toBeInTheDocument();
   });
 
-  it("repositions nodes on click (a node's transform changes)", async () => {
+  it("runs auto-layout on load (nodes are positioned at layout positions)", async () => {
     vi.mocked(fetchWorkflows).mockResolvedValue([v2Def()]);
     const { container } = render(
       <WorkflowNodeEditor isOpen onClose={() => {}} addToast={() => {}} />,
@@ -436,14 +436,25 @@ describe("WorkflowNodeEditor — U5 auto-layout", () => {
     // React Flow positions step nodes via a translate transform on their wrapper.
     const wrapperFor = (id: string) =>
       container.querySelector<HTMLElement>(`.react-flow__node[data-id="${id}"]`);
-    const before = wrapperFor("step")?.style.transform ?? "";
-    fireEvent.click(screen.getByTestId("wf-auto-layout"));
+    // After load, the step node should have been auto-laid-out (positioned).
     await waitFor(() => {
-      const after = wrapperFor("step")?.style.transform ?? "";
-      expect(after).not.toBe("");
-      expect(after).not.toBe(before);
+      const transform = wrapperFor("step")?.style.transform ?? "";
+      expect(transform).not.toBe("");
     });
   });
+
+  it("clicking auto-layout still works after initial load", async () => {
+    vi.mocked(fetchWorkflows).mockResolvedValue([v2Def()]);
+    render(
+      <WorkflowNodeEditor isOpen onClose={() => {}} addToast={() => {}} />,
+    );
+    await screen.findByTestId("wf-node-start");
+    // The auto-layout button should still be present and clickable.
+    const btn = screen.getByTestId("wf-auto-layout");
+    expect(btn).toBeInTheDocument();
+    // Clicking it should not throw.
+    fireEvent.click(btn);
+  });
 });
 
 // ── U8: step-inversion authoring (foreach/step-review/parse-steps/code) ──────

packages/dashboard/app/components/workflow-auto-layout.ts

@@ -37,8 +37,8 @@ export const WF_AUTO_LAYOUT_BAND_PADDING = 16;
 export const WF_AUTO_LAYOUT_SPACING = WF_CARD_MAX_WIDTH + WF_AUTO_LAYOUT_GAP_X;
 
 /** Left/top origin for the laid-out graph. */
-const ORIGIN_X = 40;
-const ORIGIN_Y = 40;
+const ORIGIN_X = 0;
+const ORIGIN_Y = 0;
 
 /** Row height for a stacked card (card + vertical gap). */
 const ROW_HEIGHT = WF_CARD_HEIGHT + WF_AUTO_LAYOUT_GAP_Y;