[Windows] Work mode composer rejects plain drag-and-drop file attachments (Chat/Codex modes accept them); Shift+drag works

What version of the Codex App are you using (From "About Codex" dialog)?

26.727.6591.0 (MSIX package OpenAI.Codex_26.727.6591.0_x64__2p2nqsd0c76g0)

What subscription do you have?

Team，20 USD * 12

What platform is your computer?

Windows 11 x64

What issue are you seeing?

In the unified desktop app, drag-and-drop file attachment behaves inconsistently across modes:

• Chat mode: dragging a file from Windows Explorer into the composer works — the file attaches on drop.
• Codex mode: same, works.
• Work mode: dragging a file over the composer shows a forbidden (no-drop) cursor, and dropping does nothing. The file is not attached.
• In Work mode, holding Shift while dragging the same file into the composer works and attaches it.
• The + attach button (file picker) also works normally in Work mode.

So Work mode is the only surface where a plain (no-modifier) drag-and-drop is rejected, while Shift+drag and the attach button both work.

What steps can reproduce the bug?

1. Open the desktop app on Windows (version above).
2. Switch to Work mode and open or start a thread.
3. Drag any local file (e.g. a .txt or .xlsx) from File Explorer onto the message composer without holding any modifier key.
4. Observe the forbidden cursor; release the mouse — nothing is attached.
5. Repeat while holding Shift — the file attaches.
6. Switch to Chat or Codex mode and repeat step 3 — the file attaches without needing Shift.

What is the expected behavior?

Either:

• Work mode should accept plain drag-and-drop like Chat and Codex modes do, for a consistent experience across modes; or
• if requiring Shift in Work mode is intentional, the app should surface that (e.g. a hint on drag-over) and document the gesture, instead of showing a bare forbidden cursor.

Additional information

• Verified this is not a Windows privilege/UIPI issue: both the app processes (ChatGPT.exe) and explorer.exe run at medium integrity (non-elevated), no "run as administrator" flags anywhere.
• Reproduces every time on the version above.