Stabilize flaky E2E waits for TOC init and dynamic tag selection

[Copilot]

Two E2E tests were intermittently timing out due to brittle readiness conditions: TOC initialization depended solely on window.__e2e signals, and dynamic-tag setup depended on URL mutation timing. This change hardens both waits to assert stable UI state directly.

• TOC readiness fallback in E2E helper

  • Updated WaitForTocInitializedAsync to keep signal-based waiting when window.__e2e exists, but fall back to DOM readiness when it does not.
  • Fallback now waits for TOC anchor links to be present, and treats pages as TOC-not-applicable only when heading anchors are absent.

• State-based setup in dynamic tag flake paths

  • Replaced setup assertions that waited for tags= in URL with assertions that selected-tag count increases after click.
  • Applied in the two loop-based paths that build disabled-tag scenarios, removing dependency on URL timing while preserving test intent.

• Representative change

  var selectedCountBefore = await Page.Locator(".tag-cloud-item.selected").CountAsync();
  await enabledTags[0].ClickAndExpectAsync(async () =>
      await Page.WaitForConditionAsync(
          $"() => document.querySelectorAll('.tag-cloud-item.selected').length > {selectedCountBefore}"));

[github-actions]

⏰ PR Preview Environment — Nightly Teardown

The preview environment was automatically torn down as part of the nightly cleanup (23:00 Brussels time).

To resume testing:

• Push a new commit to this branch to automatically re-deploy (full CI + new images), or
• Trigger the Redeploy PR Environment workflow manually to redeploy using the last-built image (no new commit needed).

[Copilot]

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