[FEATURE] Tab completion for file paths

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

I often need to reference files on specific paths both in and out of the project space when I am using Claude Code. It would be helpful if Claude could recognize when I am typing a path and apply tab completion similar to the CLI experience.

Proposed Solution

Assume a file with the name IMPLEMENTATION_PLAN.md is located in the docs directory of another project called Project_X. I would like to be able to type a prompt like:

"Please reference the file ../P[tab]/d[tab]/I[tab]"

And have the path autocomplete on each [tab] to produce the full path "../Project_X/docs/IMPLEMENTATION_PLAN.md"

Alternative Solutions

_No response_

Priority

Medium - Would be very helpful

Feature Category

CLI commands and flags

Use Case Example

1. I am typing a path in my prompt
2. I type ./ or ../ so the parser knows I am typing a path
3. I type the first few letters of a file or directory name and hit tab
4. If string autocompletes as far as it can
5. If user hits tab again and more than one file matches the extended prefix then the list of available files/directories is shown, if there is only one file that matches the line flashes to indicate the match is unique

Additional Context

_No response_