test(e2e): retry click on table rows when handles detach (#943)

## Problem

E2E test `Node detail loads` intermittently fails with:

> elementHandle.click: Element is not attached to the DOM

(e.g. PR #938 CI run job 73889426640.) Same flake class as #ngStats
hydration race fixed in #940.

## Root cause

```js
const firstRow = await page.$('table tbody tr');
await firstRow.click();
```

Between the `$()` and `.click()`, the nodes table re-renders from a
WebSocket push. The captured handle is detached from the new DOM, click
throws.

## Fix

Switch to a selector-based click with a small retry loop (3 attempts ×
200ms backoff), so a detach mid-attempt re-resolves a fresh element.

Test logic unchanged; just defensive against re-render between query and
click.

Co-authored-by: Kpa-clawbot <bot@example.invalid>

test-e2e-playwright.js

@@ -224,10 +224,22 @@ async function run() {
   // Test 5: Node detail loads (reuses nodes page from test 2)
   await test('Node detail loads', async () => {
     await page.waitForSelector('table tbody tr');
-    // Click first row
-    const firstRow = await page.$('table tbody tr');
-    assert(firstRow, 'No node rows found');
-    await firstRow.click();
+    // Use a stable selector + retry-on-detach pattern. Querying a row handle
+    // and clicking it later races with WebSocket-driven table re-renders that
+    // detach the original element. Click via a fresh selector each time and
+    // retry on the "not attached" error.
+    let lastErr;
+    for (let attempt = 0; attempt < 3; attempt++) {
+      try {
+        await page.click('table tbody tr:first-child', { timeout: 2000 });
+        lastErr = null;
+        break;
+      } catch (err) {
+        lastErr = err;
+        await page.waitForTimeout(200);
+      }
+    }
+    if (lastErr) throw lastErr;
     // Wait for detail pane to appear
     await page.waitForSelector('.node-detail');
     const html = await page.content();