[feat]: Support multiple windows #658
Description
Feature Summary
Allow users to open multiple Emdash windows at the same time, each with access to the same set of tasks/workspaces, but prevent the same task/workspace from being opened in more than one window at once.
Problem or Use Case
When using Emdash on multiple monitors, I often want to have multiple tasks running and see them side by side. Right now, everything is stuck in a single window, so I have to constantly switch views, which can get annoying.
Proposed Solution
Allow users to open multiple windows of Emdash, each with access to the same set of workspaces and tasks. If a workspace or task is already open in one window, it should be locked/un-openable in other windows. Instead, Emdash could show a message like “This task is already open in another window.”
Alternatives Considered
No response
Additional Context
The locking behavior is needed because tasks run through a CLI-based agent view. Letting the same task run in multiple windows would be complex to support and could cause conflicts, so each task/workspace should only be active in one window at a time.