[BUG] Cowork sidebar items appear draggable but drag-and-drop into Chat does nothing (Claude for Mac)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

In the Claude for Mac desktop application, specifically within the Cowork feature, items in the right-hand sidebar panels (Progress / Artifacts / Context) appear draggable, but drag-and-drop into the Chat input does nothing.

Details:

Selecting a file entry (including its subtitle area) enables a drag cursor/state

The UI allows starting a drag gesture toward the Chat area

Dropping the item results in no action and no feedback

This creates a misleading UX where drag-and-drop appears supported but is silently ignored.

What Should Happen?

One of the following should occur:

The dragged file/reference is inserted into the Chat input
or

Dragging is clearly disabled if unsupported (no drag cursor / no drag affordance)
or

Explicit feedback explains why dropping is not allowed

Error Messages/Logs

Steps to Reproduce

1. Open Claude for Mac

1. Enter Cowork mode

1. Look at the right sidebar (Progress, Artifacts, or Context)

1. Click to select a file entry (including the subtitle area)

1. Observe that the cursor indicates the item is draggable

1. Drag the item into the Chat input area

1. Drop the item

1. Result: Nothing happens

Claude Model

Sonnet (default)

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

Claude for Mac (Desktop App) v1.0.3218

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Affects multiple sidebar panels: Progress / Artifacts / Context

Fully reproducible

No visual indication that the drop target is invalid

Likely a UI state mismatch:

Drag affordance enabled

Chat input not registered as a valid drop target

Or drop handler intentionally disabled but UI not updated

At minimum, the draggable affordance should be disabled if drag-and-drop is not supported in Cowork.