Add batch diff review mode: show all changes together before approval (like Cursor's native agent)

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

Problem
The Claude Code VS Code extension currently offers two edit modes:

• Ask before edits – approves changes one line at a time, forcing decisions without seeing the full picture
• Edit automatically – makes all changes silently with no diff review at all

Neither option matches the workflow that Cursor's native agent provides, where ALL changes are made first and then presented together as inline diffs for the developer to review, approve, or reject — individually or all at once.

The Claude Code VS Code extension currently offers two edit modes: Ask before edits approves changes one line at a time, forcing decisions without seeing the full picture. Edit automatically makes all changes silently with no diff review at all. Neither option matches the workflow that Cursor's native agent provides, where ALL changes are made first and then presented together as inline diffs for the developer to review, approve, or reject — individually or all at once. This is a significant UX regression for teams switching from Cursor to the Claude extension.

What we want
A third mode: "Batch diff review" — Claude makes all its changes, then presents the full set of diffs together for review before committing, just like Cursor's native agent workflow.

Proposed Solution

Add a third mode: "Batch diff review" — Claude makes all its changes across all files, then pauses and presents the complete set of diffs together in VS Code's native diff viewer before anything is committed. The developer can then review all changes in context, seeing how they work together, and approve or reject them individually or all at once — exactly like Cursor's native agent workflow.

Alternative Solutions

Using git diff after "Edit automatically" works as a workaround but is cumbersome, especially in projects with submodules where you have to cd into each subfolder separately. There is currently no clean solution.

Priority

Critical - Blocking my work

Feature Category

File operations

Use Case Example

I ask Claude to make a change that touches 4 files. With "Ask before edits" I have to approve each individual line change without knowing what's coming next — I'm making decisions blind. With "Edit automatically" Claude makes all the changes silently and I have no idea what it did without manually running git diff. What I want: Claude finishes all edits, then shows me all 4 files side by side as diffs. I review them together, see how they relate, then approve or reject each one.

Additional Context

Several teams switched from Cursor to the Claude extension specifically to use the Max subscription instead of per-seat Cursor billing — but this diff workflow gap is a real pain point. Related issues: #29388, #11411, #2502. Cursor's native agent is the reference implementation for what this should look like.