Allow Aki to reorder tasks via sort order field

When manually reordering tasks via drag-and-drop in the app, Akiflow updates an internal “sort order” field. However, Aki (the AI assistant) doesn’t have access to this field through its current API toolset — the only field it can control to sequence tasks is start_datetime, which requires assigning a time.

This means Aki can’t reorder tasks in the Today view, project lists, or other views without setting a time, which isn’t ideal for users who want to keep sorting separate from scheduling.

Request: Give Aki access to a tool that can set the sort order of tasks across different views (Today, project lists, inbox, etc.) so it can reorder tasks on demand without relying on priority or start_datetime.