VSCode extension: add setting to control where diff views open

Summary

When Claude Code proposes file edits (Edit/Write tool), the diff view opens in the user's current active editor tab/group, replacing whatever file they're looking at. There's no way to control this behavior.

Request

Add a configuration option (e.g., claude-code.diffPlacement) to control where proposed diffs open in the editor. Suggested values:

• "active" — current behavior (replace active tab)
• "beside" — open in an adjacent editor group
• "new" — always open in a new editor tab without replacing the active one

Use Case

When reviewing proposed changes, I often have the relevant source file open for context. The diff replacing that tab forces me to re-navigate after accepting or rejecting the change. This is especially disruptive during multi-file edits where I want to keep reference files visible.

Current Workarounds

• Pinning the active tab (partially works but requires manual action each time)
• Setting workbench.editor.revealIfOpen: false (inconsistent results)

Environment

• VSCode on Windows 11
• Claude Code VSCode extension