[FEATURE] Allow editing proposed diffs in the approval prompt before accepting

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

Summary

In "ask before edits" mode, when Claude proposes an Edit/Write, the approval prompt shows the diff but doesn't
let me modify it inline. If I manually edit the file in my editor while the prompt is open and then approve,
Claude overwrites my changes with the buffered new_string from its tool call.

Current workaround

Reject and re-prompt Claude with "do this but change X to Y", or accept then manually fix afterward. Both add
a round-trip.

Why it matters

• Many edits are 90% right and need a one-line tweak — re-prompting wastes a model turn.
• Manual edits to the file during the prompt are silently discarded today, which is surprising.

Proposed Solution

Let the user edit the proposed new_string (or the resulting file) before approving, and have "Accept" apply
the edited version rather than the originally buffered one. Cline supports this and it's a meaningful
productivity gap for small tweaks that don't warrant re-prompting.

Alternative Solutions

_No response_

Priority

High - Significant impact on productivity

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_