<!-- CURSOR_SUMMARY -->
> [!NOTE]
> Introduces live Agent to-do tracking during local-agent runs.
> 
> - **New tool:** `update_todos` (merge/replace support) added to agent
toolset; updates per-turn `todos` in `AgentContext` and broadcasts via
`onUpdateTodos`
> - **IPC plumbing:** New `agent-tool:todos-update` channel allowlisted
in `preload`; `IpcClient` adds `onAgentTodosUpdate` and
`onChatStreamStart` hooks and forwards updates; main handler emits
updates and initializes `ctx.todos`
> - **Types:** Adds `AgentTodo` and `AgentTodosUpdatePayload`; extends
`AgentContext` with `todos` and `onUpdateTodos`
> - **UI/state:** New `agentTodosByChatIdAtom`; `TodoList` component;
`ChatInput` renders live todos; renderer subscribes to updates and
clears todos on stream start/end
> - **Tests:** E2E snapshot updated with `update_todos` tool schema
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
e2bc12f172b2b6ae15c3514e7e9c4d2b693a6e99. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

<!-- This is an auto-generated description by cubic. -->
---
## Summary by cubic
Adds an Agent TODOs tool and UI to track task progress during local
agent runs. Live updates stream to the chat and display in a collapsible
todo list, which clears when a new stream starts.

- **New Features**
- Added update_todos tool with merge/replace support and status updates;
broadcasts via onUpdateTodos.
- Introduced IPC channel agent-tool:todos-update with
IpcClient.onAgentTodosUpdate and preload whitelist.
  - Defined AgentTodo and AgentTodosUpdatePayload types.
  - Added agentTodosByChatIdAtom and cleanup on chat stream start.
- Implemented TodoList UI and wired into ChatInput to show live progress
and counts.

<sup>Written for commit e2bc12f172b2b6ae15c3514e7e9c4d2b693a6e99.
Summary will update on new commits.</sup>

<!-- End of auto-generated description by cubic. -->

---------
Co-authored-by: cubic-dev-ai[bot] <191113872+cubic-dev-ai[bot]@users.noreply.github.com>