[BUG] Update Diff view isn't quite right for overlong lines

Environment

• Platform (select one):
• [x] Anthropic API
• [ ] AWS Bedrock
• [ ] Google Vertex AI
• [ ] Other: <!-- specify -->
• Claude CLI version: v1.0.24
• Operating System: Ubuntu
• Terminal: Ubuntu Terminal

Bug Description

When Claude uses the Update tool and shows a diff, the overlong part of overlong lines gets (the ndbox in the below).
printed twice:

● Update(src/ClaudeBox.jl)
  ⎿  Updated src/ClaudeBox.jl with 1 addition and 2 removals
       488           mounts,
       489           # Environment
       490           Dict(
       491 -             # Note: juliaup PATH is set in bashrc instead to avoid being overwritten by the 
     sandbox
           - ndbox
       492 -              "PATH" => 
     "/opt/npm/bin:/opt/nodejs/bin:/opt/gh_cli/bin:/opt/git/bin:/opt/git/libe
           - xec/git-core:/usr/bin:/bin",
       491 +             # Note: PATH is set in bashrc instead - passing it here gets overwritten by the 
     sandbox
           + ndbox
       492               "HOME" => "/root",
       493               "NODE_PATH" => "/opt/npm/lib/node_modules",
       494               "npm_config_prefix" => "/opt/npm",

Steps to Reproduce

1. Ask Claude to update a long line
2. Observe diff

Expected Behavior

The line wrapping code should not print the last bit of the overlong lines.

Actual Behavior

It did print

Additional Context

$ echo $LINES
83
$ echo $COLUMNS
112