[BUG] Desktop: with OS reduced motion, the Code tab working indicator looks stuck

What happens

In Claude Desktop on Windows, the Claude mark next to a running Code tab session's status line barely animated. The image changed roughly every 20 seconds, so a session that was busy looked hung. On macOS the same indicator animates smoothly.

The cause was not in the app. Windows' Settings → Accessibility → Visual effects → Animation effects was off on this machine. I had not turned it off knowingly, and I hadn't changed the app's own Motion setting, which defaults to System. Turning "Animation effects" on fixed it immediately, without restarting the app.

Why this is a bug and not just a setting

Following the OS preference is correct. Two things around it are not:

1. The reduced-motion presentation reads as a stall. The working indicator is the main sign that a long turn is still alive. A mark that changes only every ~20 seconds is indistinguishable from a frozen UI, which is the problem #72341 reported for a different cause before it was closed by the stale bot. Reduced motion should remove movement, not the sign that the session is still running.
2. The link is invisible. The Motion row in Settings offers "System" and "Reduced", with no hint that "System" currently means "Reduced" because of a Windows accessibility switch. I only found the connection by investigating why the animation looked broken. A user who never touched either setting has no way to tell.

Expected

• With reduced motion, keep a clear "still working" signal that doesn't rely on movement. A ticking elapsed-time counter, a changing status label, or a slow cross-fade instead of a sprite animation would all work.
• In Settings → Motion, show the resolved state of "System", e.g. "System (Reduced: Windows animation effects are off)".

Environment

• Claude Desktop 2.19675.1.0 (MSIX), Windows 11 x64, build 26200
• Windows "Animation effects" off: SPI_GETCLIENTAREAANIMATION returned false
• App Settings → Motion: System (default, unchanged)

Related

• #99139 asks for the classic spark animation back and notes that the app's own reduced-motion setting "brings back a spark, but it's choppy". That is the same presentation, reached from the app setting instead of the OS.
• #72341 (closed by the stale bot): The working indicator freezes while the session is still busy, which makes a healthy session look hung.