Overlay Playground Node DNS resolution for URL-import runtimes

## Problem

WP Codebox 0.18.4 ships Playground 3.1.46, whose Node PHP.wasm `dns_get_record()` returns an empty array. Public URL importers that validate resolved addresses, including Static Site Importer, fall back to synthetic loopback resolution and correctly reject the target as private. This prevents unchanged end-to-end URL intake in disposable Codebox runtimes.

## Proposed fix

Temporarily overlay the rebuilt Node PHP.wasm packages from WordPress Playground PR #4172 until an upstream Playground release contains the fix. Record the exact upstream commit and add a runtime proof that public A/AAAA records resolve without weakening importer SSRF checks.

Upstream: https://github.com/WordPress/wordpress-playground/pull/4172

## Acceptance criteria

- `dns_get_record()` returns real public records in the Node runtime.
- SSI runs its unchanged fetch, SSRF validation, collection, and import pipeline in WP Codebox.
- The temporary overlay is provenance-documented and removable after the upstream package release.

## AI assistance

OpenAI gpt-5.6-sol via OpenCode was used to reproduce the runtime incompatibility, identify the existing upstream Playground repair, and draft this tracker. Chris Huber remains responsible for the issue and resulting changes.

Beginne bei der WP Codebox Node-Laufzeitumgebung und ihrem Einstiegspunkt für die URL-Annahme des Static Site Importer und vergleiche anschließend die neu erstellten Node PHP.wasm-Pakete aus WordPress Playground PR #4172 mit den aktuellen Playground 3.1.46-Paketen. Überprüfe, dass dns_get_record() öffentliche A/AAAA-Records zurückgibt und dass die unveränderte SSI-Fetch-, SSRF-Validierungs-, Collection- und Import-Pipeline weiterhin erfolgreich ist, wobei der Overlay-Commit für die spätere Entfernung dokumentiert wird.

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