Remove Multi-Device Docs Tester workflow - incompatible with repository structure (#814)

The Multi-Device Docs Tester workflow expected a Node.js documentation
site at `./docs/` with Astro/Starlight build system. This repository's
`./docs/` directory contains only markdown files with no `package.json`
or build infrastructure. All 8 workflow runs failed when the agent
attempted `npm install` in a non-existent package, terminating after ~2
minutes without producing output artifacts.

## Changes

- **Removed** `.github/workflows/daily-multi-device-docs-tester.md`
- **Removed**
`.github/workflows/daily-multi-device-docs-tester.lock.yml`
- **Removed** `.github/workflows/shared/docs-server-lifecycle.md` (only
used by this workflow)

## Context

This is an MCP Gateway repository, not a documentation site. The
workflow was fundamentally incompatible with the repository structure
and had a 100% failure rate since creation.

> [!WARNING]
>
> <details>
> <summary>Firewall rules blocked me from connecting to one or more
addresses (expand for details)</summary>
>
> #### I tried to connect to the following addresses, but was blocked by
firewall rules:
>
> -
`https://api.github.com/repos/github/gh-aw-mcpg/actions/runs/21783945698/artifacts`
> - Triggering command: `/usr/bin/curl curl -L -H Accept:
application/vnd.github&#43;json -H X-GitHub-Api-Version: 2022-11-28
REDACTED` (http block)
>
> If you need me to access, download, or install something from one of
these locations, you can either:
>
> - Configure [Actions setup
steps](https://gh.io/copilot/actions-setup-steps) to set up my
environment, which run before the firewall is enabled
> - Add the appropriate URLs or hosts to the custom allowlist in this
repository's [Copilot coding agent
settings](https://github.com/github/gh-aw-mcpg/settings/copilot/coding_agent)
(admins only)
>
> </details>

<!-- START COPILOT ORIGINAL PROMPT -->



<details>

<summary>Original prompt</summary>

> 
> ----
> 
> *This section details on the original issue you should resolve*
> 
> <issue_title>[agentics] Multi-Device Docs Tester failed</issue_title>
> <issue_description>### Workflow Failure
> 
> **Workflow:** [Multi-Device Docs Tester](#)  
> **Branch:** main  
> **Run URL:**
https://github.com/github/gh-aw-mcpg/actions/runs/21783945698
> 
> 
> 
> ### Action Required
> 
> Debug this workflow failure using the `agentic-workflows` agent:
> 
> ```
> /agent agentic-workflows
> ```
> 
> When prompted, instruct the agent to debug this workflow failure.
> 
> 
> > Generated from [Multi-Device Docs
Tester](https://github.com/github/gh-aw-mcpg/actions/runs/21783945698)
> > - [x] expires <!-- gh-aw-expires: 2026-02-14T17:28:25.845Z --> on
Feb 14, 2026, 5:28 PM UTC
> 
> <!-- gh-aw-agentic-workflow: Multi-Device Docs Tester,
gh-aw-tracker-id: daily-multi-device-docs-tester, run:
https://github.com/github/gh-aw-mcpg/actions/runs/21783945698
--></issue_description>
> 
> ## Comments on the Issue (you are @copilot in this section)
> 
> <comments>
> </comments>
> 


</details>


> **Custom agent used: agentic-workflows**
> GitHub Agentic Workflows (gh-aw) - Create, debug, and upgrade
AI-powered workflows with intelligent prompt routing



<!-- START COPILOT CODING AGENT SUFFIX -->

- Fixes #812

<!-- START COPILOT CODING AGENT TIPS -->
---

💡 You can make Copilot smarter by setting up custom instructions,
customizing its development environment and configuring Model Context
Protocol (MCP) servers. Learn more [Copilot coding agent
tips](https://gh.io/copilot-coding-agent-tips) in the docs.

Author: lpcox