[Bug] Keyboard input dropped in prompt box during Claude processing (macOS)

Bug Description
Keyboard input is intermittently dropped in the prompt box (macOS 27, native install)

ENVIRONMENT

• Claude Code: v2.1.283, native installation
• OS: macOS 27
• Terminals tested: Apple Terminal.app, iTerm2, Ghostty (reproduces in all three)

DESCRIPTION
When I type in the prompt input, the TUI becomes unresponsive for short periods (from milliseconds up to a few seconds). Keystrokes pressed during these stalls are lost, not buffered: they never appear, even after the stall ends or after Claude finishes working. I have to press the same key several times before the character is written.

It happens most often when I start typing my next prompt while Claude is still working, but it also happens when I start typing right after Claude has finished a turn.

STEPS TO REPRODUCE

1. Start a session with claude in any terminal (Terminal.app, iTerm2 or Ghostty).
2. Give Claude a task that takes a while.
3. While Claude is working (or right after it finishes), start typing the next prompt.
4. Some keystrokes are not registered; characters must be retyped several times.

EXPECTED
Every keystroke is registered in the prompt input, whether or not Claude is working. Input typed during a busy moment should appear once the UI catches up.

ACTUAL
Input stalls intermittently and keystrokes typed during the stall are discarded.

FREQUENCY
Several times a day.

NOTES

• Reproduces in all three terminals, so it doesn't seem terminal-specific.
• Happens in short sessions too, not only long ones near the context limit.
• Does NOT happen when I type into the same session from my phone via Remote Control. This points to the local terminal input handling rather than the session itself.
• Lost keystrokes (not just delayed ones) suggest stdin is being dropped or not read while the render loop is busy, rather than buffered.

Environment Info

• Platform: darwin
• Terminal: xterm-256color
• Version: 2.1.285
• Feedback ID: f92e6f1c-1c23-40a4-95a7-5c087d6f2d24

Errors

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