Suggested test: copilot/skill-per-auth

## Motivation

Link to the gh-aw PR: github/gh-aw#42594 — Support per-skill GitHub auth in frontmatter `skills`

PR #42594 extended `skills:` frontmatter to accept object-form entries with per-skill `github-token` or `github-app` credentials, enabling multi-org skill installs with distinct auth. The compiler now emits a dedicated install step per skill entry, each scoped to the provided token. No existing test exercises the object-form `skills:` entry; all current skill-using tests use plain string refs.

## Proposed test

- **Workflow file**: `test-copilot-skill-per-auth.md`
- **Trigger**: `workflow_dispatch`
- **Engine**: copilot
- **Safe output**: `create-issue` (simple confirmation)
- **Variant**: standard

## Minimal test prompt sketch

Define a `skills:` block containing both a plain string ref (existing format) and an object-form ref with `github-token: ${{ secrets.GH_AW_TEST_PAT }}` pointing to an existing skill. Ask the agent to create a summary issue confirming both skills are available. This exercises the compiler's per-entry install step generation and confirms the object-form token is correctly scoped at install time.

## New fixtures or secrets needed

Minimal smoke path: reuse `GH_AW_TEST_PAT` (already available) for the per-skill token — same credential, different structural path. A true cross-org test would require a separate secret (e.g. `SKILL_ORG_TOKEN`) pointing to a different org's token; that can be deferred.

## Notes

- The `--use-samples` path does not exercise skill installs, so this test is only meaningful in live-engine mode.
- Object-form `github-app` entries (app-generated tokens with `client-id`/`private-key`) require more fixture setup and can be a separate follow-up test.
- The compiler emits one install step per skill entry in object form; a compilation smoke (`gh aw compile`) is a quick first check even without running the workflow.

> [!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/28508312058) · 49.8 AIC · ⌖ 6.78 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 proposed test/copilot/skill-per-auth.md workflow using the stated workflow_dispatch trigger, copilot engine, standard variant, and create-issue output. First run gh aw compile as a smoke check, then use live-engine mode with the existing GH_AW_TEST_PAT secret; done means the workflow confirms both plain-string and object-form skills are available.

Written by the indexing model from the issue text.