[FEATURE] Provide a prominent toggle to stop auto-submitting file contents

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 work on very large files, such as ipynb files that have large amounts of data embedded. The vscode Claude Code extension automatically includes and autosubmits the current file I'm working on, which chews through tokens if I don't remember to click on the file repeatedly dozens of times a day to disable it. That's an expensive nuisance and babysitting job.

Proposed Solution

Create a prominent toggle in the prompt widget to submit the current file or not, and remember that. And/or create a setting where I can just stop this behavior entirely. I'd always rather purposefully opt in when I want to submit content to you.

Alternative Solutions

I've searched for whether there was a way to achieve this now, and I don't think there is.

Priority

High - Significant impact on productivity

Feature Category

Interactive mode (TUI)

Use Case Example

1. I'm working on a large ipynb.
2. I type a prompt. Claude automatically includes the file as context to the prompt.
3. I can disable that by clicking on the file below the prompt, but I have to remember to do that repeatedly.

Additional Context

_No response_