[BUG] Claude Desktop (Windows): system-tray icon invisible when app theme differs from the Windows taskbar mode — wrong-contrast glyph selected (mirror of #65343)

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?

On Windows, the Claude Desktop system-tray icon renders as a blank/white square (invisible) whenever the app's appearance (userThemeMode) differs from the Windows taskbar color ("Windows mode"). The app is fully functional — only the tray glyph is invisible.

What Should Happen?

The tray glyph should contrast with the Windows taskbar and stay visible regardless of the app's own theme. Fix: select the tray icon from the taskbar / Windows-mode color (registry SystemUsesLightTheme) instead of nativeTheme.shouldUseDarkColors — light taskbar → Tray-Win32.ico (black glyph), dark taskbar → Tray-Win32-Dark.ico (white glyph). Alternatively ship a monochrome template tray image and let Windows handle contrast automatically.

Error Messages/Logs

None — no error is logged. The app runs normally; this is a silent icon-selection defect (the wrong-contrast glyph is drawn). The only evidence is visual: an empty/white tray cell on a light taskbar.

Steps to Reproduce

Windows → Settings → Personalization → Colors → set "Choose your default Windows mode" = Light (taskbar/tray is light).
Open Claude Desktop → Settings → set Appearance = Dark (config: userThemeMode: "dark").
Minimize Claude to the system tray.
Look at the Claude icon in the tray (taskbar or the ^ overflow flyout).
Result: a blank/white square — the app draws the white glyph (Tray-Win32-Dark.ico) on the light taskbar. Expected: the black glyph (Tray-Win32.ico) for contrast. Deterministic every launch with this theme combo, and on a separate freshly-installed Windows 11 machine.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude Desktop 1.15962.1.0 (MSIX/Store) — Desktop app, not the CLI

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

This is the Claude Desktop GUI app (MSIX/Store), so the CLI-oriented fields above (Model, Platform, Terminal/Shell) aren't really applicable. Mirror issue #65343 ("tray icon black on Windows when Windows mode is Dark") is the same root cause with themes reversed; it was closed as invalid on a misdiagnosis — the .ico is not empty, it's a valid white glyph (pixel-verified). Please consider reopening/linking. Workaround: match the app theme to the taskbar (app→Light or Windows mode→Dark).