Shift+drag file to chat not working in VS Code UI (works in CLI)

Bug Report

Environment:

• Claude Code version: 2.1.7
• VS Code extension: anthropic.claude-code@2.1.7
• Platform: Linux (Ubuntu 24.04, kernel 6.14.0-37-generic)

Issue

Shift+drag to add files to chat works correctly in terminal/CLI mode but does NOT work in VS Code UI extension.

This feature was working before recent updates - stopped working on Jan 14, 2026.

Steps to reproduce

1. Open Claude Code in VS Code (UI mode)
2. Try to Shift+drag a file into the chat input
3. File is not added to the conversation

Expected behavior

Shift+drag should add files in both CLI and VS Code UI

Actual behavior

• ✅ CLI terminal: Shift+drag works
• ❌ VS Code UI: Shift+drag does not work

Additional context

Both CLI and extension are on the same version (2.1.7). Reloading VS Code window did not help.