ADMIN-006: Verify Configuration Page functionality

[amankum2004]

PR Description: Add E2E Coverage for Configuration Page

Summary

• Adds end-to-end coverage for Configuration page behavior in the new UI.
• Introduces a dedicated Page Object for the Config page.
• Makes assertions configurable through testConfig so tests are reusable across environments.

What Changed

• Added ConfigsPage page object:
  • airflow-core/src/airflow/ui/tests/e2e/pages/ConfigsPage.ts
  • Encapsulates Config page selectors and helpers (navigate, waitForLoad, row parsing, section/key matching).
• Added Config E2E spec:
  • airflow-core/src/airflow/ui/tests/e2e/specs/configs.spec.ts
  • Covers page render, Admin menu navigation, and row validations.
  • Handles both supported runtime states:
    • Config table exposed.
    • Config values hidden with 403 Forbidden message.
• Extended Playwright testConfig:
  • airflow-core/src/airflow/ui/playwright.config.ts
  • Added configPage options:
    • path
    • expectedHeading
    • expectsTableData
    • expectedSection
    • expectedKey
    • forbiddenMessage
• Updated E2E docs:
  • airflow-core/src/airflow/ui/tests/e2e/README.md
  • Documented new Config-page-related env vars.

Test Coverage Added

• verify configuration displays
• verify configuration page is accessible via Admin menu
• verify configuration section and key are rendered (when TEST_CONFIG_PAGE_EXPECTS_TABLE_DATA=true)
• verify section, key and value are populated in configuration rows (when TEST_CONFIG_PAGE_EXPECTS_TABLE_DATA=true)

Acceptance Criteria Mapping

• Page Object Model pattern: Met (ConfigsPage + spec uses page object methods).
• Tests use testConfig: Met (testConfig.configPage drives path and assertions).
• Works across Chromium, Firefox, WebKit: Met by Playwright project configuration and spec compatibility.

Notes

• The UI route under test is /configs (plural).
• By default, tests assume many environments hide config values for security:
  • TEST_CONFIG_PAGE_EXPECTS_TABLE_DATA=false (default) validates the 403 Forbidden state.
• To validate table content in an environment that exposes configuration values:
  • Set TEST_CONFIG_PAGE_EXPECTS_TABLE_DATA=true
  • Optionally override TEST_CONFIG_PAGE_SECTION and TEST_CONFIG_PAGE_KEY.

[amankum2004]

@vatsrahul1001 Hello sir, I have created this PR to fix the issue - UI E2E Test || ADMIN-006: Verify Configuration Page functionality #60572
Kindly review the request. If any changes or modifications are required from my side then please comment.