terminal-setup writes invalid TOML escape sequence in Alacritty config

Description

The /terminal-setup command writes an invalid TOML escape sequence to the Alacritty config file (~/.config/alacritty/alacritty.toml).

It produces:

[[keyboard.bindings]]
key = "Return"
mods = "Shift"
chars = "\x1b\r"

\x is not a valid TOML escape sequence, which causes Alacritty to fail to parse the config file.

Expected behavior

The generated config should use TOML-compatible Unicode escapes:

chars = "\^[\r"

Steps to reproduce

1. Have an existing valid ~/.config/alacritty/alacritty.toml
2. Run /terminal-setup in Claude Code
3. Alacritty fails to reload config with a parse error at the chars line

Environment

• Claude Code CLI
• Alacritty terminal
• Linux (Arch)