Suggested test: copilot/sandbox-agent-runtime-gvisor

## Motivation

Link to the gh-aw PR: github/gh-aw#44796 — feat: add `sandbox.agent.runtime: gvisor` for gVisor container runtime support

## Proposed test

- **Workflow file**: `test-copilot-sandbox-agent-runtime-gvisor.md`
- **Trigger**: `workflow_dispatch`
- **Engine**: copilot
- **Safe output**: `create-issue`
- **Variant**: standard (gVisor changes the container runtime; nosandbox would defeat the purpose)

## Minimal test prompt sketch

Compile and dispatch a workflow with `sandbox.agent.runtime: gvisor` and `sandbox.agent.sudo: true` in frontmatter. The agent should create an issue confirming it ran. Verifies that the gVisor install step ran and the AWF config included `containerRuntime: gvisor`.

## New fixtures or secrets needed

None — but requires confirming gVisor is available on the hosted runner before enabling the test.

## Notes

New compiler-side frontmatter field with no existing coverage. `test-copilot-network-isolation.md` exercises sandbox networking but not the runtime field. A nosandbox variant would not apply here since the feature is sandbox-specific.

> [!WARNING]
>
> Firewall blocked 1 domain
>
> The following domain was blocked by the firewall during workflow execution:
>
> - `awmgmcpg`
>> To allow these domains, add them to the `network.allowed` list in your workflow frontmatter:
>
> ```yaml
> network:
> allowed:
> - defaults
> - "awmgmcpg"
> ```
>
> See [Network Configuration](https://github.github.com/gh-aw/reference/network/) for more information.
>
>

> Generated by [🔍 Suggest New E2E Tests](https://github.com/githubnext/gh-aw-test/actions/runs/29147036798) · 27 AIC · ⌖ 5.64 AIC · ⊞ 5.6K · [◷](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)

Start with the existing test-copilot-network-isolation.md workflow and the proposed test file, test-copilot-sandbox-agent-runtime-gvisor.md. Compile and dispatch the workflow with the stated gVisor frontmatter after confirming hosted-runner availability. Done means the agent creates an issue and the run verifies the gVisor install step and containerRuntime: gvisor in the AWF configuration.

Written by the indexing model from the issue text.