bug: theme selector crashes when filtering produces no results

[renormalize]

Description

The theme selector dialog crashes with a TypeError when typing characters during theme search that produce no matching results.

[17:02:02] [ERROR] Error: undefined is not an object (evaluating 'opt.value')
    TypeError: undefined is not an object (evaluating 'opt.value')
        at onMove (src/cli/cmd/tui/component/dialog-theme-list.tsx:26:17)
        at moveTo (src/cli/cmd/tui/ui/dialog-select.tsx:83:11)
        at <anonymous> (src/cli/cmd/tui/ui/dialog-select.tsx:65:9)

This is because the .value property is accessed on an undefined.

Plugins

N/A

OpenCode version

1.1.23

Steps to reproduce

1. Open the theme selector in opencode.
2. Start typing a theme name which is not listed, I typed sonokai.
3. When typing the letter n for sonokai, the application errors, and prints out error logs in the console.

Screenshot and/or share link

Operating System

macOS 26.2

Terminal

Ghostty 1.2.3