[BUG] Filepath autocomplete no longer works after Tab key was reassigned to thinking mode

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?

Description:

In the previous version of Claude Code, pressing Tab would trigger filepath autocomplete when typing partial paths in the input.
This was extremely useful for quickly navigating and referencing files in the project.

In the current version, Tab has been reassigned to toggle extended thinking mode, which breaks this workflow.

Impact:
This significantly slows down workflow for users who frequently reference files in conversations.

What Should Happen?

A keyboard shortcut should be available to trigger filepath autocomplete, similar to the previous Tab behavior.

Suggested solutions:

1. Assign a new keyboard shortcut for filepath autocomplete (e.g., Ctrl+Space or Ctrl+/)
2. Document the new shortcut in the interactive-mode documentation
3. Consider making keyboard shortcuts customizable

Error Messages/Logs

Steps to Reproduce

1. Start typing a partial filepath (e.g., src/co)
2. Press Tab (now toggles thinking mode instead of autocomplete)
3. Try alternative shortcuts: Ctrl+Space, Ctrl+/, Alt+/, Esc then / - none trigger filepath autocomplete

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0.14

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_