Add patch tool for applying diff/patch files

[louismorgner]

Summary

The native runtime lacks a tool for applying patch files, which is useful for large-scale refactoring and structured code changes.

What OpenCode does

OpenCode has a patch tool that can apply standard patch/diff files to the workspace.

Proposed implementation

Add a Patch tool to the native tool registry that:

• Accepts a unified diff / patch string
• Applies it to the appropriate files in the workspace
• Reports success/failure per hunk
• Falls back gracefully on conflicts

Priority

P2 — useful for large refactoring tasks

🤖 Generated with Claude Code