Suggested test: copilot/create-issue-large-body

## Motivation

Link to the gh-aw PR: github/gh-aw#43911 — _fix: add maxLength: 65536 to create_issue and create_discussion body fields_

`create_issue.body` and `create_discussion.body` lacked an explicit `maxLength`, so the SM-IS-01 validator applied a 10 KB global cap and silently truncated large bodies. The fix adds `maxLength: 65536` to both fields. There is currently no regression test verifying that a body larger than 10 KB is not truncated.

## Proposed test

- **Workflow file**: `test-copilot-create-issue-large-body.md`
- **Trigger**: `workflow_dispatch`
- **Engine**: copilot
- **Safe output**: `create-issue`
- **Variant**: standard

## Minimal test prompt sketch

Instruct the agent to create an issue whose body is a generated text block of approximately 12–15 KB (e.g. a numbered list with enough entries to exceed 10 KB). The E2E harness can assert that the created issue body length exceeds 10,000 characters, confirming the old cap is not applied.

## New fixtures or secrets needed

None — standard `create-issue` safe output within `githubnext/gh-aw-test`.

## Notes

The `samples:` block in the source `.md` should include a body that is realistically large (>10 KB) so `--use-samples` mode also exercises the boundary. This scenario applies equally to `create-discussion` (github/gh-aw#43911 fixed both), but a single `create-issue` test is sufficient for the initial regression. Cross-engine coverage (claude, codex) is straightforward once the copilot variant passes.

> [!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/28856843748) · 41 AIC · ⌖ 6.66 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 test-copilot-create-issue-large-body.md as a workflow_dispatch Copilot E2E test with the described create-issue safe output and standard variant. Start from the proposed workflow settings and sample prompt, then verify the harness creates a body over 10,000 characters in both normal and --use-samples modes; no new fixtures or secrets should be needed.

Written by the indexing model from the issue text.