[FEATURE] Add "Open Editors" / attach all open tabs as chat context

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

Often in a chat with Claude Code in the VSCode extension, I want to discuss the files I already have open in my editor.

Today the only ways to attach files as context are:

• @-mentioning each file individually in the chat input
• Relying on the automatic ide_selection from the active editor, which only covers one file and only what's currently highlighted

For tasks that span several open files (e.g. a frontend component + its hook + its test), I end up @-mentioning 5–10 paths by hand before I can even start the conversation. It's slow, error-prone, and a constant source of friction compared to other VSCode AI extensions.

Proposed Solution

Add an "Open Editors" option to the chat input's add-context menu.

Ideal behavior:

• One click attaches every file currently open in
• Attached files appear as removable chips/pills, same as individual @-mentions, so I can drop any I don't want before sending.
• GitHub Copilot's VSCode extension already does exactly this: its "+" add-context button has "Open Editors" as the first option, which attaches every open tab in one click. It's the fastest path to "here's what I'm currently working on" and the gap is noticeable when switching between the two extensions.

Alternative Solutions

• @-mentioning each file by hand — works, but tedious for more than 2–3 files and easy to forget one.
• Pasting a list of file paths into the prompt — Claude can read them via its tools, but this bypasses the proper context-attachment UI and wastes turns on file reads.
• Highlighting code to use the auto-attached ide_selection — only covers one file at a time.

Priority

Medium - Would be very helpful

Feature Category

Other

Use Case Example

Scenario: I'm working on a bug in a React form component.

1. In VSCode I have these tabs open: FormComponent.tsx, useFormState.ts, FormComponent.test.tsx, api/submitForm.ts, and types/form.ts — the natural "working set" for this bug.
2. I open the Claude Code chat panel and want to ask: "the submit handler is firing twice — what's wrong?"
3. Today: I have to type @FormComponent.tsx @useFormState.ts @FormComponent.test.tsx @api/submitForm.ts @types/form.ts before my actual question. Easy to miss one, and it interrupts the flow of writing the prompt.
4. With this feature: I click "Open Editors", see 5 files attached as chips, and just type my question. Total time saved per chat: ~20–30 seconds, plus less cognitive overhead.
5. Over a day of debugging this adds up to real time.

Additional Context

Reference implementation: GitHub Copilot's VSCode extension. Click the "+" / add-context button in its chat input — "Open Editors" is the first item in the menu and attaches every open tab in one click. This issue is essentially a request for parity with that UX.

Environment:

• Claude Code VSCode extension version 2.1.144
• Platform: macOS Sequoia version 15.7.4