Add Azure DevOps work items to Up next

### Summary

The global Up next panel (cross-session inbox of assigned PRs / issues) currently only surfaces GitHub items. For projects backed by Azure DevOps repos — which the app already supports as projects — Up next is empty. Requesting that assigned ADO work items appear alongside GitHub items in the same panel. (Active ADO PRs would be a natural extension once work items land.)

### Repro

**Preconditions:** the bundled `ado-mcp` server is authenticated against an Azure DevOps organisation, and the signed-in identity has at least one assigned open work item.

1. Create a project in this Copilot CLI desktop app pointing at one or more Azure DevOps Git repos (no GitHub remote).
2. Open the global Up next panel.
3. **Expected:** assigned ADO work items appear.
4. **Actual:** Up next is empty for that project. The project metadata exposed to the agent shows the GitHub repo field as unresolved for ADO-backed repos, which appears to leave the existing inbox path without a provider to query.

### Proposed shape

- Per-project optional config: one ADO org + project + WIQL query. Suggested default: `[System.AssignedTo] = @Me AND [System.State] NOT IN ('Closed','Removed','Done','Completed')` — treat as a starting default; ADO states are process-dependent so users should be able to override.
- Auth: reuse the ADO token already accepted by the bundled `ado-mcp` server. No new auth surface.
- Render inline in Up next with a small provider badge so users can tell GitHub items from ADO items.

Active ADO PRs (author / reviewer) and multi-source / multi-org support are natural follow-ups, out of scope for this ask.

### Workaround I'm running today

A per-project scheduled workflow queries my ADO queue via `ado-mcp` and renders an `inbox` widget inside a session — useful but session-scoped, so the global Up next stays empty.

### Related (adjacent symptoms of non-GitHub project gaps — not claiming shared root cause)

- #3060 — `store_memory` fails when origin is not on `github.com`
- #3378 — `/memory` "Manage stored memories" link 404s for non-GitHub repos

### Environment

- Copilot CLI v1.0.62, macOS / Tauri desktop
- Bundled `ado-mcp` server, authenticated against an Azure DevOps organisation

先追蹤全域 Up next 面板及其現有的 GitHub 項目提供者，然後檢查 Azure DevOps 專案中繼資料和內建的 ado-mcp 驗證如何被公開。完成的標準是：已指派的開啟中 ADO 工作項目會帶有提供者徽章出現在 Up next 中，使用可設定的組織、專案和 WIQL 設定，且不新增新的驗證介面。

由索引模型根據 Issue 內容生成。