[aw] Markdown Dedup failed

### Workflow Failure

**Workflow:** [Markdown Dedup](https://github.com/githubnext/gh-aw-workshop/blob/main/.github/workflows/markdown-dedup.md)
**Branch:** main
**Run:** https://github.com/githubnext/gh-aw-workshop/actions/runs/35104988340

> [!WARNING]
> **Engine Failure**: The `copilot` engine terminated unexpectedly.

**Last agent output:**
```
Check your COPILOT_PROVIDER_API_KEY or COPILOT_PROVIDER_BEARER_TOKEN.
Changes +0 -0
Duration 1m 4s
Tokens ↑ 544.0k (251.5k cached) • ↓ 8.9k
Resume copilot --resume=dea5b44a-4d57-4bf9-a928-8c74f880a577
Authentication failed with provider at http://172.30.0.30:10002 (HTTP 403).
Check your COPILOT_PROVIDER_API_KEY or COPILOT_PROVIDER_BEARER_TOKEN.
Changes +0 -0
Duration 1s
Resume copilot --resume=983352f0-8bdc-4550-b694-d40d79f3c7e1
```

### Action Required

**Assign this issue to an agent** to debug and fix the issue.

Debug with any coding agent

Use this prompt with any coding agent (GitHub Copilot, Claude, Gemini, etc.):

````
Debug the agentic workflow failure using https://raw.githubusercontent.com/github/gh-aw/main/debug.md

The failed workflow run is at https://github.com/githubnext/gh-aw-workshop/actions/runs/35104988340
````

Manually invoke the agent

Debug this workflow failure using your favorite Agent CLI and the `agentic-workflows` prompt.

- Start your agent
- Load the `agentic-workflows` skill from `.github/skills/agentic-workflows/SKILL.md` or
- Type `debug the agentic workflow markdown-dedup failure in https://github.com/githubnext/gh-aw-workshop/actions/runs/35104988340`

> [!TIP]
>
> Stop reporting this workflow as a failure
>
> To stop a workflow from creating failure issues, set `report-failure-as-issue: false` in its frontmatter:
> ```yaml
> safe-outputs:
> report-failure-as-issue: false
> ```
>
>

> Generated from [Markdown Dedup](https://github.com/githubnext/gh-aw-workshop/actions/runs/35104988340) · copilot · 86.6 AIC · [◷](https://github.com/search?q=repo%3Agithubnext%2Fgh-aw-workshop+is%3Aissue+%22gh-aw-workflow-id%3A+markdown-dedup%22&type=issues)
> - [x] expires on Sep 23, 2026, 2:00 PM UTC

Start with .github/workflows/markdown-dedup.md and the linked workflow run, then read .github/skills/agentic-workflows/SKILL.md or the referenced debug.md. Trace the copilot engine's HTTP 403 authentication failure and confirm the workflow can be rerun without the engine terminating unexpectedly.

Written by the indexing model from the issue text.