[BUG] Desktop: first click on an unfocused mod Pane only focuses it; Button onPress does not fire

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report
• [x] I am using the latest version of Claude Code

What's Wrong?

On the desktop surface, clicking a Button in a mod Pane that does not have focus only moves focus to the pane. onPress does not fire, so a second click is needed. Once the pane has focus, clicks press normally (after the mod keeps the focus ring on the pressed control with $.ui.focus).

What Should Happen?

The first click on a Button in an unfocused Pane should fire ui.press / onPress, the same as a click on a focused Pane.

Error Messages/Logs

No error. With `ui.press` and `ui.render` hooks logging every event, the first click on an unfocused pane
produces only a re-render of the Pane with isFocused=true and no ui.press. The next click produces ui.press.

Steps to Reproduce

1. Load a mod that opens a Pane ($.ui.open({ id, title })) and draws a Button with an onPress handler in its ui.render hook.
2. In the Claude desktop app (Code tab), open the Pane.
3. Click in the prompt box so the Pane loses focus.
4. Click the Button once. onPress does not fire; the Pane only gains focus.
5. Click the Button again. onPress fires.

Claude Model

Opus

Is this a regression?

I don't know

Claude Code Version

2.1.293 (Claude Code), Claude desktop app 2.26454.2

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other (Claude desktop app, Code tab)

Additional Information

Related mod/desktop issues: #99217, #99449.