test(ui): CheckpointsTable covers fragment layout + locale sub-line

ui/src/pages/AppsTab/AppDeploymentPage/CheckpointsTable.test.tsx

@@ -26,25 +26,27 @@ const stoppedDep: Deployment = {
 };
 
 function expand() {
-  fireEvent.click(screen.getByRole('button', { name: /checkpoints/i }));
+  fireEvent.click(screen.getByRole('button', { name: /expand|collapse/i }));
 }
 
 describe('CheckpointsTable', () => {
-  it('defaults to collapsed — header visible, rows hidden', () => {
+  it('defaults to collapsed — label + trigger visible, rows hidden', () => {
     wrap(<CheckpointsTable deployments={[stoppedDep]} versions={[v6]}
       currentDeploymentId={null} jarRetentionCount={5} onSelect={() => {}} />);
-    expect(screen.getByRole('button', { name: /checkpoints \(1\)/i })).toBeInTheDocument();
+    expect(screen.getByText('Checkpoints')).toBeInTheDocument();
+    expect(screen.getByRole('button', { name: /expand \(1\)/i })).toBeInTheDocument();
     expect(screen.queryByText('v6')).toBeNull();
     expect(screen.queryByText('my-app-1.2.3.jar')).toBeNull();
   });
 
-  it('clicking header expands to show rows', () => {
+  it('clicking trigger expands to show rows; label flips to Collapse', () => {
     wrap(<CheckpointsTable deployments={[stoppedDep]} versions={[v6]}
       currentDeploymentId={null} jarRetentionCount={5} onSelect={() => {}} />);
     expand();
     expect(screen.getByText('v6')).toBeInTheDocument();
     expect(screen.getByText('my-app-1.2.3.jar')).toBeInTheDocument();
     expect(screen.getByText('alice')).toBeInTheDocument();
+    expect(screen.getByRole('button', { name: /collapse \(1\)/i })).toBeInTheDocument();
   });
 
   it('row click invokes onSelect with deploymentId', () => {
@@ -105,4 +107,23 @@ describe('CheckpointsTable', () => {
     expand();
     expect(screen.getByText(/show older \(5\)/i)).toBeInTheDocument();
   });
+
+  it('Deployed sub-line is locale-formatted (not the raw ISO)', () => {
+    wrap(<CheckpointsTable deployments={[stoppedDep]} versions={[v6]}
+      currentDeploymentId={null} jarRetentionCount={5} onSelect={() => {}} />);
+    expand();
+    // Raw ISO would contain 'T' and end in 'Z' — localized form must not.
+    const raw = '2026-04-23T10:35:00Z';
+    expect(screen.queryByText(raw)).toBeNull();
+    // Use the createdBy cell as an anchor and walk to the sibling Deployed cell.
+    const row = screen.getByText('alice').closest('tr')!;
+    const cells = row.querySelectorAll('td');
+    // Column order: Version, JAR, Deployed by, Deployed, Strategy, Outcome, chevron
+    const deployedCell = cells[3];
+    expect(deployedCell).toBeDefined();
+    const text = deployedCell.textContent ?? '';
+    expect(text).not.toContain('T10:35');
+    expect(text).not.toContain('Z');
+    expect(text.length).toBeGreaterThan(0);
+  });
 });