Grok Build file edits do not show diffs in the TUI

Summary

When Jcode uses the Grok Build ACP provider, the agent edits files but the TUI does not show a file diff the way Claude does. The user only sees a status title such as Editing src/lib.rs, with no +/- view.

Reproduction

1. Log in to Grok Build (jcode login --provider grok-build).
2. /model grok-build:grok-4.6.
3. Ask Grok to edit a source file.

Expected

The TUI renders an edit/write tool row with a unified diff, matching Claude.

Actual

Grok Build applies the edit itself over ACP and notifies the client with session/update tool_call (title, locations, optional content: diff). The Grok Build runtime previously mapped that to StreamEvent::StatusDetail only, so ToolUseStart / ToolInput / ToolResult never reached the TUI.

Environment

• Provider: Grok Build ACP (grok-build-acp)
• Model: grok-build:grok-4.6