Sending several comments at once

### Feature summary

_No response_

### What problem are you trying to solve?

Doing several changes at once while limiting the number of agent turns (and tokens at the same time). I like this process when a PR is open: you can do a full review of changes and then ask the agent to fix all of these. I think it would be nice to have the same capability locally.

### Proposed solution

* When adding a comment, add an option to "Add to review" instead of "Send"ing right away

* When comments were added to the review, add a button to send all comments at once

### Workflow impact

_No response_

### Installation context

_No response_

### Additional context

_No response_

Start by tracing the local comment composer and the flow that submits comments, then inspect how review comments are represented and sent. Add a way to queue comments instead of sending them immediately and a control to submit all queued comments; done means several comments can be reviewed and sent together locally.

索引モデルが issue の本文から書いたものです。