[information-architecture] Full-loop stale issues setup hides shared stale-label configuration

## Information Architecture Findings

### 1. Full-loop setup separates a shared selector from the setup path
**Area:** Picker placement / Progressive disclosure
**Component(s):**
- `docs/workflows/gh-agent-workflows/stale-issues.md:19-29`
- `gh-agent-workflows/stale-issues-investigator/example.yml:13-16`
- `gh-agent-workflows/stale-issues-remediator/example.yml:12-15`
- `docs/workflows/gh-agent-workflows/stale-issues.md:44-51, 91-98`
- `gh-agent-workflows/stale-issues-investigator/README.md:40-48`
- `gh-agent-workflows/stale-issues-remediator/README.md:30-38`

**Problem:**
The “Full loop (investigator + remediator)” quick-install path tells users to copy both workflow files, but neither example includes a `with:` block showing `stale-label`. The shared selector is documented later in separate Inputs tables, away from the setup flow.

Because both workflows must use the same `stale-label`, users can easily customize one workflow and not the other. That breaks the pairing: investigator labels issues with one value while remediator looks for another.

**Suggested improvement:**
Expose `stale-label` directly in both example workflow files (commented `with:` block), and add an explicit note in the full-loop section that both workflows must use identical `stale-label` values.

## Suggested Actions
- [ ] Add commented `with: stale-label: "stale"` blocks to both stale-issues example workflow files.
- [ ] Mirror the same configuration snippet in the docs example blocks.
- [ ] Add a short “keep `stale-label` identical across investigator/remediator” warning in the full-loop install section.

> [!NOTE]
>
> 🔒 Integrity filtering filtered 1 item
>
> Integrity filtering activated and filtered the following item during workflow execution.
> This happens when a tool call accesses a resource that does not meet the required integrity or secrecy level of the workflow.
>
> - issue:#unknown (`search_issues`: has lower integrity than agent requires. The agent cannot read data with integrity below "approved".)
>
>

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