[FEATURE] Mobile app: Edit/Write tool prompts don’t let user preview the diff before approving

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

Description:
When the agent invokes the Edit or Write tool, the permission prompt on mobile shows the file path and an “output” section, but the output section stays at “running…” until I approve, and there’s no way to expand/view the actual proposed diff before deciding.
Steps to reproduce:

1. Use Claude Code on the mobile app
2. Have the agent propose an Edit to an existing file
3. Tap into the pending tool call to review

Expected: I should be able to see exactly what old_string → new_string change is being proposed before approving.

Actual: The preview area stays “running…” with no way to see the proposed change. I have to either approve blind or rely on the agent’s chat-message description of the diff.

Impact: This forces approve-blind behavior on mobile and undermines the value of the permission prompt (which exists so I can verify before changes land). The agent’s chat-message description and the actual tool call may not always match exactly, so the prompt should be the source of truth, not the chat.

Environment: Claude Code mobile app, [iOS / Android — fill in], app version [check Settings].

Proposed Solution

Render the proposed old_string and new_string (or a unified diff between them) inside the permission prompt on mobile, the same way the desktop/web UI does.

Alternative Solutions

_No response_

Priority

High - Significant impact on productivity

Feature Category

Interactive mode (TUI)

Use Case Example

_No response_

Additional Context

_No response_