Suggested test: copilot/safe-output-metadata-field

## Motivation

Link to the gh-aw PR: github/gh-aw#48363 — Add sanitization-safe `metadata` channel for body-based safe outputs

The new `metadata` field is a first-class structured object on safe-output items that survives HTML comment sanitization. No existing test exercises this field.

## Proposed test

- **Workflow file**: `test-copilot-safe-output-metadata-field.md`
- **Trigger**: `workflow_dispatch`
- **Engine**: copilot
- **Safe output**: `create-issue` (or `add-comment`) with a `metadata` key set to a small JSON object
- **Variant**: standard

## Minimal test prompt sketch

Instruct the agent to create an issue and attach a structured `metadata` object (e.g. `{"source": "e2e-test", "version": 1}`) to the safe-output item. The harness should assert that the issue was created and that the metadata field was accepted without validation errors.

## New fixtures or secrets needed

None. Standard `githubnext/gh-aw-test` repo is sufficient.

## Notes

The feature also applies to `add-comment`, `update-issue`, etc. A single `create-issue` variant is sufficient to validate the new metadata path. The `samples:` block should include a `metadata` key so the test runs deterministically with `--use-samples`.

> Generated by [🔍 Suggest New E2E Tests](https://github.com/githubnext/gh-aw-test/actions/runs/30346216775) · sonnet46 · 24.7 AIC · ⌖ 5.9 AIC · ⊞ 6.1K · [◷](https://github.com/search?q=repo%3Agithubnext%2Fgh-aw-test+is%3Aissue+%22gh-aw-workflow-call-id%3A+githubnext%2Fgh-aw-test%2Fsuggest-new-e2e-tests%22&type=issues)

Use test-copilot-safe-output-metadata-field.md as the entry point and run the standard workflow with --use-samples. Follow the proposed workflow_dispatch, copilot, and create-issue setup; done means the issue is created and its structured metadata is accepted without validation errors.

Written by the indexing model from the issue text.