We no longer rely on the `author` field to tell if a change was made by
the user or the agent. The `author` can be set to `User` in many
situations that are not really user-made edits, such as saving a file,
accepting a change, auto-formatting, and more. I started tracking and
fixing some of these cases, but found that inspecting changes in
`diff_base` is a more reliable method.
Also, we no longer show empty diffs. For example, if the user adds a
line and then removes the same line, the final diff is empty, even
though the buffer is marked as user-changed. Now we won't show such
edit.
There are still some issues to address:
- When a user edits within an unaccepted agent-written block, this
change becomes a part of the agent's edit. Rejecting this block will
lose user edits. It won't be displayed in project notifications, either.
- Accepting an agent block counts as a user-made edit.
- Agent start to call `project_notifications` tool after seeing enough
auto-calls.
Release Notes:
- N/A