Fix stale internal workflow naming docs for downstream health

> [!CAUTION]
> Protected files were modified in this change.
> This pull request is in `request_review` mode and requires explicit human scrutiny before merge.
>
> Protected files: `.github/workflows/workflow-patrol.lock.yml`, `.github/workflows/workflow-patrol.md`

## Summary

This PR resolves the stale internal-workflow naming/behavior text drift identified in issue #1755.

### Changes

- Replaced stale `downstream-users` with `internal-downstream-health` in `gh-agent-workflows/DEVELOPING.md`.
- Updated `.github/workflows/workflow-patrol.md` guidance to reflect current internal workflow behavior:
- only `upgrade-check` and `workflow-patrol` skip trigger/example/README and use schedule/dispatch
- `internal-downstream-health` remains internal but follows the standard trigger/example/README + `workflow_call` pattern
- Recompiled workflow outputs so `.github/workflows/workflow-patrol.lock.yml` matches source updates.

Closes \#1755.

> [!WARNING]
>
> Firewall blocked 1 domain
>
> The following domain was blocked by the firewall during workflow execution:
>
> - `models.dev`
>> To allow these domains, add them to the `network.allowed` list in your workflow frontmatter:
>
> ```yaml
> network:
> allowed:
> - defaults
> - "models.dev"
> ```
>
> See [Network Configuration](https://github.github.com/gh-aw/reference/network/) for more information.
>
>

---
[What is this?](https://ela.st/github-ai-tools) | [From workflow: Trigger Text Auditor](https://github.com/elastic/ai-github-actions/actions/runs/30914595455)

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---

> [!NOTE]
> This was originally intended as a pull request, but the git push operation failed.
>
> **Original error:** pushSignedCommits: refusing unsigned push for branch 'fix-issue-1755-internal-workflow-text-13061ff6e41ccdc6': Signed-commit payload violates file-protection policy (request_review): .github/workflows/workflow-patrol.lock.yml, .github/workflows/workflow-patrol.md
>
> **Workflow Run:** [View run details and download bundle artifact](https://github.com/elastic/ai-github-actions/actions/runs/30914595455)
>
> The bundle file is available in the `agent` artifact in the workflow run linked above.

To create a pull request with the changes:

```sh
# Download the artifact from the workflow run
gh run download 30914595455 -n agent -D /tmp/agent-30914595455

# Fetch the bundle into a temporary ref, then update the local branch
git fetch /tmp/agent-30914595455/aw-fix-issue-1755-internal-workflow-text.bundle refs/heads/fix-issue-1755-internal-workflow-text:refs/bundles/create-pr-fix-issue-1755-internal-workflow-text-13061ff6e41ccdc6-84579d3f
git update-ref refs/heads/fix-issue-1755-internal-workflow-text-13061ff6e41ccdc6 refs/bundles/create-pr-fix-issue-1755-internal-workflow-text-13061ff6e41ccdc6-84579d3f
git checkout fix-issue-1755-internal-workflow-text-13061ff6e41ccdc6
# Ensure the working tree matches the updated branch
git reset --hard
# Remove the temporary bundle ref
git update-ref -d refs/bundles/create-pr-fix-issue-1755-internal-workflow-text-13061ff6e41ccdc6-84579d3f

# Push the branch to origin
git push origin fix-issue-1755-internal-workflow-text-13061ff6e41ccdc6

# Create the pull request
gh pr create --title 'Fix stale internal workflow naming docs for downstream health' --base main --head fix-issue-1755-internal-workflow-text-13061ff6e41ccdc6 --repo elastic/ai-github-actions
```

Start by reviewing gh-agent-workflows/DEVELOPING.md and .github/workflows/workflow-patrol.md to compare the documented workflow names and trigger behavior with the current workflows. Recompile the workflow outputs and verify that .github/workflows/workflow-patrol.lock.yml matches the source updates. Done means the stale name is replaced, the guidance reflects the stated exceptions, and the generated lock file is synchronized.

Written by the indexing model from the issue text.