Add integration tests for /events Audit log page (Part 1)

[Prajwal7842]

This PR adds playwright integration tests for /events Audit log page for Airflow UI.

Covers following things from listed down in the issues:

Audit Logs Display

1. Navigate to the Audit Logs page (/events)
2. Verify the logs table is displayed
3. Verify log entries show: timestamp, event type, DAG ID, user, etc.
4. Verify pagination works
5. Verify column sorting works

Search/Filter Logs

1. Verify search input is visible

closes: #59931
releated: #59028

The integration tests were locally run 5+ times consecutively and all runs passed successfully to avoid any flakiness
Sample run:

[Prajwal7842]

@vatsrahul1001 can you take a look. Builds are passing now. Thanks

[vatsrahul1001]

Thanks, I will review it soon!

[vatsrahul1001]

@Prajwal7842 Thanks for the PR! A few things to address:

1. Test naming - Remove "should" prefix (use "verify ..." instead of "should verify ...")

2. Remove hardcoded waits - waitForTimeout(5000) is slow and fragile. Use proper Playwright assertions:
   await expect(async () => {
   const indicator = await eventsPage.getColumnSortIndicator(0);
   expect(indicator).not.toBe("none");
   }).toPass({ timeout: 10_000 });

3. Move DAG trigger to beforeAll - Current "Events with Generated Data" tests depend on first test running. Move triggerDag to beforeAll for proper isolation

4. Column selectors are fragile - Using .nth(1), .nth(2) breaks if column order changes. Use text/role-based selectors:
   this.eventTypeColumn = page.getByRole("columnheader", { name: /event/i });
   5. Sorting test weak - Only checks indicator, not actual sort order. Capture data before/after and verify it changed

5. Filter test incomplete - Only opens menu, doesn't apply filter. Add test that applies filter and verifies results

6. Fix pagination URL - Missing / prefix and limit=1 is too small:
   return "/events?limit=5&offset=0";
   8. Remove waitForTimeout method

Let me know if you have questions!

[vatsrahul1001]

This adds 10 seconds of unnecessary wait time

await expect(async () => {
  const sortIndicator = await eventsPage.getColumnSortIndicator(0);
  expect(sortIndicator).not.toBe("none");
}).toPass({ timeout: 10_000 });

[vatsrahul1001]

Move trigger dag to beforeAll

test.describe("Events with Generated Data", () => {
  const testDagId = testConfig.testDag.id;

  test.beforeAll(async ({ browser }) => {
    test.setTimeout(3 * 60 * 1000);
    const context = await browser.newContext({ storageState: AUTH_FILE });
    const page = await context.newPage();
    const dagsPage = new DagsPage(page);
    
    await dagsPage.triggerDag(testDagId);
    await context.close();
  });

  test.beforeEach(({ page }) => {
    eventsPage = new EventsPage(page);
  });

[vatsrahul1001]

If column order changes, all tests break.
Maybe we can use something like below

this.timestampColumn = page.getByRole("columnheader", { name: /when/i });
this.eventTypeColumn = page.getByRole("columnheader", { name: /event/i });
this.userColumn = page.getByRole("columnheader", { name: /user/i });

[vatsrahul1001]

This doesn't verify the data is actually sorted.
Capture data before/after and verify order

[vatsrahul1001]

Test only checks that the filter UI exists:

• Opens filter menu
• Verifies menu items visible
• Closes menu

This is NOT a filter test - it's just checking the filter UI is present.

[Prajwal7842]

@Prajwal7842 Thanks for the PR! A few things to address:

1. Test naming - Remove "should" prefix (use "verify ..." instead of "should verify ...")
2. Remove hardcoded waits - waitForTimeout(5000) is slow and fragile. Use proper Playwright assertions:
   await expect(async () => {
   const indicator = await eventsPage.getColumnSortIndicator(0);
   expect(indicator).not.toBe("none");
   }).toPass({ timeout: 10_000 });
3. Move DAG trigger to beforeAll - Current "Events with Generated Data" tests depend on first test running. Move triggerDag to beforeAll for proper isolation
4. Column selectors are fragile - Using .nth(1), .nth(2) breaks if column order changes. Use text/role-based selectors:
   this.eventTypeColumn = page.getByRole("columnheader", { name: /event/i });
   5. Sorting test weak - Only checks indicator, not actual sort order. Capture data before/after and verify it changed
5. Filter test incomplete - Only opens menu, doesn't apply filter. Add test that applies filter and verifies results
6. Fix pagination URL - Missing / prefix and limit=1 is too small:
   return "/events?limit=5&offset=0";
   8. Remove waitForTimeout method

Let me know if you have questions!

Thanks @vatsrahul1001 for the review. I have addressed the comments.
For point (5), regarding integration tests for filter, I am working on it in the follow up diff. Thanks.