[information-architecture] PR Actions Detective docs example uses read-only PR permission

## Information Architecture Findings

### 1. PR Actions Detective shows a non-working permission in the docs-page example
**Area:** Consistency
**Component(s):** `docs/workflows/gh-agent-workflows/pr-actions-detective.md`, `gh-agent-workflows/pr-actions-detective/example.yml`
**Problem:** The docs page's inline **Example workflow** places `pull-requests: read` in the permissions block, while the installable example in the workflow directory uses `pull-requests: write`. Users who copy the docs-page example instead of downloading `example.yml` can configure the workflow in a location they trust (the docs example block) but end up with permissions that don't match the workflow's comment-posting behavior.

**Evidence:**
- `docs/workflows/gh-agent-workflows/pr-actions-detective.md` (lines 49-54) shows:
- `issues: write`
- `pull-requests: read`
- `gh-agent-workflows/pr-actions-detective/example.yml` (lines 7-13) shows:
- `issues: read`
- `pull-requests: write`

**Suggested improvement:**
Align the docs-page example permissions with `gh-agent-workflows/pr-actions-detective/example.yml` so both entry points present the same control placement and capability assumptions.

## Suggested Actions
- [ ] Update `docs/workflows/gh-agent-workflows/pr-actions-detective.md` example permissions to match `gh-agent-workflows/pr-actions-detective/example.yml`.
- [ ] Add a short note near the example clarifying that PR comment output requires `pull-requests: write`.

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