VS Code/Cursor extension: add line numbers to in-chat diff displays

Feature Request

Context: Using the Claude Code extension in VS Code / Cursor.

Current behavior: When the extension shows a diff preview in the chat panel (the side-by-side before/after view), there are no line numbers displayed on either side.

Problem: Without line numbers, it's hard to orient yourself in the file — especially for edits in the middle of a large file. You can see what changed but not where in the file it sits without cross-referencing the editor manually.

Suggested behavior: Add line numbers to both sides of the in-chat diff display, matching the line numbering from the actual file. This is standard in most diff viewers (GitHub, VS Code's own diff editor, etc.) and would make it much easier to quickly contextualize an edit.

Small UX improvement, likely straightforward to implement.