Azure DevOps support for /delegate command

### Describe the feature or problem you'd like to solve

The /delegate command currently only works with GitHub repositories. I work primarily with Azure DevOps (ADO) repositories and cannot use this feature. Many enterprise developers use ADO, so this limits the reach of one of the CLI's most powerful features.

### Proposed solution

Extend /delegate to support Azure DevOps repositories, leveraging the existing ADO tooling already built into the CLI (ado-repo_create_pull_request, ado-repo_update_pull_request, etc.).
Since Microsoft owns both GitHub and ADO, this integration would be a natural fit.

Benefits:

- Same seamless delegated workflow for ADO users
- Broader enterprise adoption
- Leverages existing ADO MCP tools already in the CLI

### Example prompts or workflows

- /delegate fix the bug in UserService.cs → Creates a PR in my ADO repo with the fix
- /delegate add unit tests for the new API endpoint → Delegates test creation to remote agent, opens ADO PR
- /delegate refactor this module to use dependency injection → Complex refactoring delegated and PR created in ADO
- /delegate implement the feature described in work item #12345 → Integrates with ADO work items
- /delegate update documentation for the new release → Documentation changes delegated with ADO PR

### Additional context

The CLI already has robust ADO integration via MCP tools (I've successfully used ado-repo_create_pull_request, ado-repo_update_pull_request, etc.). The building blocks exist - it's a
matter of wiring /delegate to use these tools when the remote is an ADO repository instead of GitHub.