[FEATURE] Don't truncate long diff lines (2000-char cap hides edits in long paragraphs)

Preflight Checklist

• I have searched existing requests and this feature hasn't been requested yet
• This is a single feature request (not multiple features)

Problem Statement

Diff lines longer than 2000 characters are cut off and shown as … [+N chars] (Edit/Write diffs in the transcript and permission prompts). Noticed after updating to 2.1.276.

In Markdown and similar files, a whole paragraph is often one long line. If Claude changes a word past char 2000, the diff shows no visible change. I can't properly review or approve the edit then.

Unless I'm missing something, there's no setting or env var to change this.

Proposed Solution

Either:

• a setting to disable or raise the limit, or
• truncation that always keeps the changed region of a line visible (show context around the word-diff instead of cutting at a fixed offset).

Alternative Solutions

No response

Priority

Medium - Would be very helpful

Feature Category

Interactive mode (TUI)

Use Case Example

1. I have a .md file with a paragraph that's a single ~3000-char line.
2. I ask Claude to reword a sentence near the end of it.
3. The Edit diff shows the line cut off with … [+N chars]; the actual change is invisible.
4. With the change, I'd see and verify the edit directly in the diff.

Additional Context

Claude Code 2.1.276, Debian 12, kitty.

No files or tests are named. Start by tracing the Edit/Write diff rendering used in transcript output and permission prompts, then reproduce the behavior with a Markdown line longer than 2000 characters and a change near its end. Done means the changed region remains visible, either through configurable or context-aware truncation, with coverage for the long-line case.