When edit failed, scrollbar is badly drawn

[jeanlaurent]

Had a Edit 1 failed: old text not found and before the scroll bar was out of bounds

[Pnkcaht]

Hi, I'll take a look and submit a pull request about it.

[Pnkcaht]

Summary

Hi again @jeanlaurent , I opened a PR that addresses the issue you reported around the edit_file tool rendering behavior when an edit fails.

Previously, when an edit failed (for example, when the target text was not found), the TUI still attempted to render a diff. This could lead to inconsistent layout calculations and, in some cases, put the editor scrollbar out of bounds, making the UI behave incorrectly.

With this change, diff rendering is explicitly skipped when the tool execution fails. In error cases, the TUI now renders only the formatted error message, ensuring the layout remains stable and the failure is clearly communicated to the user.

PR: #1422