[BUG] left and right cursor navigation and delete key work, sometimes.

Environment

• Platform (select one):
• [x] Anthropic API
• [ ] AWS Bedrock
• [ ] Google Vertex AI
• [ ] Other: <!-- specify -->
• Claude CLI version:1.0.70
• Operating System: Ubuntu 24.04
• Terminal: Gnome terminal

Bug Description

Aside from the still-broken @-file browsing (#5247), the latest claude code now sometimes decides to swallow and ignore repeated keystrokes -- holding the left or right cursor key, or the delete key, will work for 20-30 characters, and then just hang.

Also, sometimes typing will wedge -- like the javascript event loop is busy with something other than input. Please consider using a background thread (or threads) for anything taking longer than 10ms -- waiting seconds to see if a keystroke was registered is not great for a terminal user interface.

If there are any profiling or logging I can enable to help you locally reproduce, I'd be happy to help.