[BUG] Tab completion broken for ! prefix bash commands

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Tab completion no longer works when typing bash commands with the ! prefix. When I press Tab while typing a command or path after !, nothing happens. Previously, Tab would complete command names and file paths.

What Should Happen?

Pressing Tab after ! should complete shell commands and file paths, like it did in previous versions.

Steps to Reproduce

1. Start Claude Code
2. Type !npm in (partial command)
3. Press Tab
4. Observe: No completion happens
5. Expected: Should complete to !npm install

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Not certain of exact version, but worked before Tab was repurposed from "Toggle Thinking mode" to completing suggested prompts.

Claude Code Version

2.0.76

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

Tab completion for !-prefixed input is contextually distinct from suggested prompt completion. When input starts with !, we're in "bash mode" and Tab should complete shell commands/paths. These two uses don't conflict, so both could work based on context.