test(e2e): add get-verification and idempotency steps to api_docs_with_children scenario

[Copilot]

001-initial-apply in the api_docs_with_children scenario only validated plan changes via expect files — it never confirmed documents were actually persisted on Konnect, and had no idempotency check to catch spurious UPDATE plans on re-apply.

Changes

• 001-get-sms-api-documents — added after 000-apply; calls get api documents --api-name "SMS API" -o json and asserts sms-errors and sms-authentication are present with status: published, plus total count of 4:

  - select: "[?slug=='sms-errors'] | [0]"
    expect:
      fields:
        slug: sms-errors
        status: published
  - select: "length(@)"
    expect:
      fields:
        "@": 4

• 002-idempotency — runs plan -f portal.yaml -f apis.yaml --mode apply against the same overlay and asserts total_changes: 0, catching any broken diff logic that would produce spurious UPDATEs on subsequent runs:

  - select: summary
    expect:
      fields:
        total_changes: 0

[Copilot]

Pull request overview

This PR strengthens the portal/api_docs_with_children E2E scenario by validating that API documents are actually persisted in Konnect after the initial apply, and by adding an idempotency check to catch unexpected UPDATEs on re-plan.

Changes:

• Add a post-apply get api documents --api-name "SMS API" -o json verification step asserting expected slugs/statuses and total document count.
• Add an idempotency plan --mode apply step asserting summary.total_changes: 0 on the same inputs.