[BUG] Text-selection context menu has no "Copy selection" — all copy actions copy the whole message

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:
When I highlight part of an assistant message, the floating context menu offers:

• Copy message
• Copy as Markdown
• Attach selection as context
• Pin as chapter

None of these copies only the highlighted text — "Copy message" and "Copy as
Markdown" both copy the ENTIRE message. There is no way to copy just the
selected fragment from the menu, and Ctrl+C also grabs the whole message.

Expected:

• A "Copy selection" entry in the menu, OR
• Ctrl+C / the menu should copy only the highlighted text when a partial

selection is active.

Environment:

• Claude Code desktop app on Windows 11
• Reproducible on any assistant message by selecting a partial line

What Should Happen?

When I highlight part of a message and copy, only the highlighted text should be
copied to the clipboard — either via a "Copy selection" entry in the context menu,
or by Ctrl+C respecting the active partial selection. Currently every copy action
("Copy message", "Copy as Markdown") copies the entire message instead.

Error Messages/Logs

N/A - no error thrown. This is a UI/UX behavior issue, not a crash.

Steps to Reproduce

1. Open any conversation in the Claude Code desktop app.
2. In an assistant message, highlight only part of the text (a few words / one line).
3. The floating menu appears: "Copy message", "Copy as Markdown",

"Attach selection as context", "Pin as chapter".

1. Click "Copy message" or "Copy as Markdown" (or press Ctrl+C).
2. Paste into any text editor.

Result: the ENTIRE message is pasted, not the highlighted selection.
Expected: only the highlighted text is copied.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

1.18286.0.0 (Claude desktop app, Windows / MSIX)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_