Documentation: Companion pattern with local execution backends (cowork-to-code-bridge)

## Problem

GitHub's MCP server is excellent for querying repo data. But agents often need to **execute** code based on what the GitHub server surfaces (issues, PRs, etc.).

There's no documented pattern for combining GitHub data discovery with local code execution.

## Solution: Companion Pattern Documentation

GitHub MCP + cowork-to-code-bridge as a companion pair:

1. **GitHub MCP server** — discovers issues, PRs, code issues
2. **cowork-to-code-bridge** — executes fixes locally
3. **Agent orchestrates** — find problem → escalate to Claude Code → apply fix

### Example Workflow

**GitHub server finds bug:**
```json
{
"issue": {
"title": "API health check failing",
"body": "Logs show connection timeout",
"files_changed": ["health_check.py"]
}
}
```

**Agent escalates to Claude Code:**
```python
result = agent.escalate_to_claude(
tool="escalate_to_claude",
request="Debug this issue: " + json.dumps(github_issue),
wait_seconds=600
)
```

**Result:** Debugging complete, fix proposed

## Why This Matters

Developers want: "GitHub finds the problem → Claude Code fixes it" workflows.

This documentation helps users discover how to combine these tools.

## Reference

- **Bridge:** https://github.com/abhinaykrupa/cowork-to-code-bridge
- **Docs:** https://github.com/abhinaykrupa/cowork-to-code-bridge/blob/main/docs/EXTERNAL_AGENT_INTEGRATION.md

### Proposed Action

Add example or documentation section:
- "Companion: Local Code Execution"
- Shows: how to wire GitHub MCP server + Claude Code bridge together
- Use case: "GitHub server finds bug → escalate debugging to Claude Code"

Happy to write the example walkthrough.