fix: resolve flaky team-management E2E test (#28575)

* fix: resolve flaky team-management E2E test

Fix two failure modes in the 'Can create teams via Wizard' test:

1. Strict mode violation: locator('[data-testid=new-team-btn]') resolves to
   2 elements during Next.js streaming/hydration. Fixed by using .first().

2. Race condition in disband assertion: raw .count() check doesn't wait for
   UI to update after team deletion. Replaced with Playwright's auto-retrying
   toBeHidden() assertion with a 10s timeout.

Co-Authored-By: romitgabani1 <romitgabani1.work@gmail.com>

* chore: remove explanatory comments per review feedback

Co-Authored-By: romitgabani1 <romitgabani1.work@gmail.com>

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Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>