fix goal view properties toggle

ui/src/pages/GoalDetail.test.tsx

@@ -0,0 +1,26 @@
+// @vitest-environment node
+
+import { describe, expect, it } from "vitest";
+import { renderToStaticMarkup } from "react-dom/server";
+import { GoalPropertiesToggleButton } from "./GoalDetail";
+
+describe("GoalPropertiesToggleButton", () => {
+  it("shows the reopen control when the properties panel is hidden", () => {
+    const html = renderToStaticMarkup(
+      <GoalPropertiesToggleButton panelVisible={false} onShowProperties={() => {}} />,
+    );
+
+    expect(html).toContain('title="Show properties"');
+    expect(html).toContain("opacity-100");
+  });
+
+  it("collapses the reopen control while the properties panel is already visible", () => {
+    const html = renderToStaticMarkup(
+      <GoalPropertiesToggleButton panelVisible onShowProperties={() => {}} />,
+    );
+
+    expect(html).toContain("opacity-0");
+    expect(html).toContain("pointer-events-none");
+    expect(html).toContain("w-0");
+  });
+});