[Bug] Ctrl + Backspace Incorrectly Handles Russian Text Deletion

Bug Description
Summary
Ctrl + Backspace does not work correctly with Russian words: instead of deleting the last word up to the space, it deletes the entire line.

Environment

• Client: claude-code (CLI)
• OS: macOS
• Terminal: PyCharm integrated terminal
• Keyboard layout: Russian

Steps to Reproduce

1. Launch claude-code in PyCharm terminal on macOS
2. Type a Russian sentence, for example:

``
текст на русском языке
``

1. Press Ctrl + Backspace

Expected Result
Only the last word should be deleted up to the previous space — in this case, языке.

Actual Result
The entire line is deleted.

Control Case
For English text, for example:

text on english language

Ctrl + Backspace correctly deletes only the last word (language).

Impact
Any Russian text input breaks the standard editing behavior, making it difficult to work in the CLI when mixing Russian and English.

Environment Info

• Platform: darwin
• Terminal: pycharm
• Version: 2.0.0
• Feedback ID: e9b2e70e-25e4-4ce8-b397-0ab70cde4c01

Errors

[{"error":"Error: Plugin source missing\n    at epZ (/$bunfs/root/claude:856:37064)\n    at epZ (/$bunfs/root/claude:856:37763)\n    at gHY (/$bunfs/root/claude:857:4198)\n    at gHY (/$bunfs/root/claude:857:4263)\n    at bHY (/$bunfs/root/claude:857:1664)\n    at bHY (/$bunfs/root/claude:857:1971)\n    at <anonymous> (/$bunfs/root/claude:858:3098)\n    at <anonymous> (/$bunfs/root/claude:858:3293)\n    at processTicksAndRejections (native:7:39)","timestamp":"2025-09-29T23:04:12.398Z"}]