[Demo][Agent Apps] Evaluate agent app for dependency risk triage

## Demo goal
Demonstrate extensibility via Marketplace Agent Apps.

## Requested change
Create `demo-app/integrations/agent-app-evaluation.md` with:
- Candidate agent app name
- Install/config notes
- Inputs required from this repo
- Expected output in PR review workflow
- Security/governance considerations

## Presenter cue
Use this issue while showing "install app -> appears in workflow -> specialized value" narrative.

Create demo-app/integrations/agent-app-evaluation.md and research a candidate Marketplace Agent App for dependency risk triage. Document its name, installation and configuration notes, repository inputs, expected PR review output, and security/governance considerations; done means all five requested sections support the install-to-workflow presentation narrative.

Written by the indexing model from the issue text.