test(canvas): cover flow resize lock

Add hook-level regression coverage proving useCanvasFlowReconciliation preserves local node state while the shared resize lock is active. The test harness now supports driving the resize ref the same way production interactions do.

components/canvas/__tests__/use-canvas-flow-reconciliation.test.ts

@@ -39,6 +39,7 @@ type HarnessProps = {
   previousConvexNodeIdsSnapshot: Set<string>;
   pendingLocalPositionPins?: Map<string, { x: number; y: number }>;
   preferLocalPositionNodeIds?: Set<string>;
+  isResizingRefOverride?: { current: boolean };
 };
 
 const latestStateRef: {
@@ -81,7 +82,8 @@ function HookHarness(props: HarnessProps) {
     props.preferLocalPositionNodeIds ?? new Set<string>(),
   );
   const isDraggingRef = useRef(props.isDragging);
-  const isResizingRef = useRef(props.isResizing);
+  const internalIsResizingRef = useRef(props.isResizing);
+  const isResizingRef = props.isResizingRefOverride ?? internalIsResizingRef;
 
   useEffect(() => {
     nodesRef.current = nodes;
@@ -93,8 +95,8 @@ function HookHarness(props: HarnessProps) {
 
   useEffect(() => {
     isDraggingRef.current = props.isDragging;
-    isResizingRef.current = props.isResizing;
+    internalIsResizingRef.current = props.isResizing;
-  }, [props.isDragging, props.isResizing]);
+  }, [props.isDragging, props.isResizing, internalIsResizingRef]);
 
   useCanvasFlowReconciliation({
     convexNodes: props.convexNodes,
@@ -286,4 +288,105 @@ describe("useCanvasFlowReconciliation", () => {
       },
     ]);
   });
+
+  it("keeps local nodes unchanged while resize-lock is active", async () => {
+    container = document.createElement("div");
+    document.body.appendChild(container);
+    root = createRoot(container);
+    const sharedIsResizingRef = { current: false };
+
+    await act(async () => {
+      root?.render(
+        React.createElement(HookHarness, {
+          initialNodes: [
+            {
+              id: "node-1",
+              type: "image",
+              position: { x: 320, y: 180 },
+              width: 640,
+              height: 360,
+              data: { label: "local" },
+            },
+          ],
+          initialEdges: [],
+          convexNodes: [
+            {
+              _id: asNodeId("node-1"),
+              _creationTime: 1,
+              canvasId: asCanvasId("canvas-1"),
+              type: "image",
+              positionX: 320,
+              positionY: 180,
+              width: 640,
+              height: 360,
+              data: { label: "local" },
+            } as Doc<"nodes">,
+          ],
+          convexEdges: [] as Doc<"edges">[],
+          storageUrlsById: {},
+          themeMode: "light",
+          isDragging: false,
+          isResizing: false,
+          isResizingRefOverride: sharedIsResizingRef,
+          resolvedRealIdByClientRequest: new Map<string, Id<"nodes">>(),
+          pendingConnectionCreateIds: new Set<string>(),
+          previousConvexNodeIdsSnapshot: new Set(["node-1"]),
+        }),
+      );
+    });
+
+    const nodesBeforeResize = latestStateRef.current?.nodes;
+
+    sharedIsResizingRef.current = true;
+
+    await act(async () => {
+      root?.render(
+        React.createElement(HookHarness, {
+          initialNodes: [
+            {
+              id: "node-1",
+              type: "image",
+              position: { x: 320, y: 180 },
+              width: 640,
+              height: 360,
+              data: { label: "local" },
+            },
+          ],
+          initialEdges: [],
+          convexNodes: [
+            {
+              _id: asNodeId("node-1"),
+              _creationTime: 1,
+              canvasId: asCanvasId("canvas-1"),
+              type: "image",
+              positionX: 20,
+              positionY: 40,
+              width: 280,
+              height: 200,
+              data: { label: "server" },
+            } as Doc<"nodes">,
+          ],
+          convexEdges: [] as Doc<"edges">[],
+          storageUrlsById: {},
+          themeMode: "light",
+          isDragging: false,
+          isResizing: true,
+          isResizingRefOverride: sharedIsResizingRef,
+          resolvedRealIdByClientRequest: new Map<string, Id<"nodes">>(),
+          pendingConnectionCreateIds: new Set<string>(),
+          previousConvexNodeIdsSnapshot: new Set(["node-1"]),
+        }),
+      );
+    });
+
+    expect(latestStateRef.current?.nodes).toBe(nodesBeforeResize);
+    expect(latestStateRef.current?.nodes[0]).toMatchObject({
+      id: "node-1",
+      type: "image",
+      position: { x: 320, y: 180 },
+      width: 640,
+      height: 360,
+      data: { label: "local" },
+    });
+  });
 });