fix(tarko): support new str_replace_editor response structure

[ulivz]

Summary

Added support for new str_replace_editor panelContent.content structure while preserving legacy code.

New supported structure:

{
  "output": "File created successfully at: /home/gem/lynx_cross_platform_framework_report.md",
  "error": null,
  "path": "/home/gem/lynx_cross_platform_framework_report.md",
  "prev_exist": false,
  "old_content": null,
  "new_content": "...markdown text..."
}

Routing logic:

• File edit (has old_content and new_content) → diff_result renderer
• File creation (has only new_content) → file_result renderer
• Error case (has error) → command_result renderer

Checklist

• My change does not involve the above items.

[netlify]

✅ Deploy Preview for agent-tars-docs ready!

Name	Link
🔨 Latest commit	a143e07
🔍 Latest deploy log	https://app.netlify.com/projects/agent-tars-docs/deploys/68b5cdab5e2f9c00081ac5c6
😎 Deploy Preview	https://deploy-preview-1332--agent-tars-docs.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.