Suggested test: copilot/private-to-public-flows

## Motivation

Link to the gh-aw PRs: github/gh-aw#45113 — implement `private-to-public-flows: allow` as a `tools.github` frontmatter field; github/gh-aw#45158 — fix CLI proxy default policy to block private repos in public repos by default.

## Proposed test

- **Workflow file**: `test-copilot-private-to-public-flows.md`
- **Trigger**: `workflow_dispatch`
- **Engine**: copilot
- **Safe output**: `create-issue`
- **Variant**: standard

## Minimal test prompt sketch

Configure the workflow with `tools.github.private-to-public-flows: allow` in frontmatter and ask the agent to read a file from this same public repo and create an issue summarising it. This exercises the compiler pipeline (frontmatter → struct → gateway JSON) for the new field and confirms the opt-in does not break a basic cross-visibility operation.

## New fixtures or secrets needed

None — `githubnext/gh-aw-test` is public so the new restrictive default applies automatically; the opt-in field is exercised within the workflow frontmatter.

## Notes

No existing test uses `tools.github.private-to-public-flows`. The change was also validated by a CLI proxy policy fix (PR #45158) so regression risk is real. All three engines would eventually benefit, but propose copilot only for now.

> [!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/29240055947) · 24.4 AIC · ⌖ 5.53 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)

Create the named workflow file, test-copilot-private-to-public-flows.md, using the proposed workflow_dispatch trigger, copilot engine, create-issue output, and private-to-public-flows frontmatter. Start by reviewing the test workflow conventions in this repository, then run the workflow and confirm it reads a file from the public repository and creates an issue summarising it without requiring new fixtures or secrets.

Written by the indexing model from the issue text.