[Bug]: Cmd+F in the right panel does nothing on a new thread #35164

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/web

Steps to reproduce

Follow-up to #34345 (fixed by #34346).

1. Start a new thread (a draft: nothing sent yet), with the right panel open.
2. Press Cmd+T, then F, to open a Files tab. Focus stays on the + button.
3. Press Cmd+F (Ctrl+F on Windows and Linux).

Expected behavior

Cmd+F focuses the Files tab's Search files box, as it does on a saved thread since #34346.

Actual behavior

Nothing happens. Focus stays on +.

On a saved thread the same steps work. Cmd+F on a file tree row also works on a draft, because the tree handles that key itself.

Diagnosis from the source (main @ dd9c2f8):

• With focus anywhere in the right panel, mod+f resolves to preview.find.
• previewCommand in apps/web/src/shortcuts/chatRouteCommands.ts dispatches the action only when the route is a saved thread (readRouteThreadRef returns null for a draft route), so on a draft it is dropped.
• The same gate drops the other preview shortcuts (refresh, zoom, focus URL) on a draft.

Impact

Minor bug or occasional failure

Version or commit

main @ dd9c2f8

Environment

macOS 27.2, desktop dev build (vp run dev:desktop).