Upstream frontend widgets layout logic (#531)

* Upstream frontend widgets layout logic

* Add back LGraphNode.freeWidgetSpace

* nit

* update expectations

test/utils/spaceDistribution.test.ts

@@ -0,0 +1,40 @@
+import { describe, expect, it } from "vitest"
+import { type SpaceRequest, distributeSpace } from "@/utils/spaceDistribution"
+
+describe("distributeSpace", () => {
+  it("should distribute space according to minimum sizes when space is limited", () => {
+    const requests: SpaceRequest[] = [
+      { minSize: 100 },
+      { minSize: 100 },
+      { minSize: 100 },
+    ]
+    expect(distributeSpace(300, requests)).toEqual([100, 100, 100])
+  })
+
+  it("should distribute extra space equally when no maxSize", () => {
+    const requests: SpaceRequest[] = [{ minSize: 100 }, { minSize: 100 }]
+    expect(distributeSpace(400, requests)).toEqual([200, 200])
+  })
+
+  it("should respect maximum sizes", () => {
+    const requests: SpaceRequest[] = [
+      { minSize: 100, maxSize: 150 },
+      { minSize: 100 },
+    ]
+    expect(distributeSpace(400, requests)).toEqual([150, 250])
+  })
+
+  it("should handle empty requests array", () => {
+    expect(distributeSpace(1000, [])).toEqual([])
+  })
+
+  it("should handle negative total space", () => {
+    const requests: SpaceRequest[] = [{ minSize: 100 }, { minSize: 100 }]
+    expect(distributeSpace(-100, requests)).toEqual([100, 100])
+  })
+
+  it("should handle total space smaller than minimum sizes", () => {
+    const requests: SpaceRequest[] = [{ minSize: 100 }, { minSize: 100 }]
+    expect(distributeSpace(100, requests)).toEqual([100, 100])
+  })
+})