Caps Lock produces [57358u in VS Code integrated terminal (v2.1.83)

Description

After updating to v2.1.83, pressing Caps Lock in the VS Code integrated terminal produces visible [57358u text. This is the Kitty keyboard protocol encoding for Caps Lock (keycode 57358) leaking through as unhandled input.

Environment

• Claude Code version: 2.1.83
• Previous working version: 2.1.81
• OS: WSL2 (Linux 6.6.87.2-microsoft-standard-WSL2)
• Editor: VS Code with Claude Code extension
• Shell: bash

Steps to Reproduce

1. Open VS Code with Claude Code extension
2. Start a Claude Code session in the integrated terminal
3. Press Caps Lock

Expected Behavior

Caps Lock keypress is consumed silently by Claude Code's input handler.

Actual Behavior

[57358u is printed as visible text in the terminal.

Additional Context

• This was not present in v2.1.81 — regression introduced in v2.1.83.
• Initially observed in only some VS Code windows; gradually spread to all open sessions as they picked up the new version.
• Does not occur in other (non-Claude Code) VS Code integrated terminals, confirming the issue is specific to Claude Code's terminal keyboard protocol handling.
• The [57358u sequence is CSI 57358 u — the Kitty keyboard protocol encoding for Caps Lock. Claude Code enables this protocol on its terminal but is not consuming the Caps Lock key event.