[BUG] Claude Code Intellij plugin showing UTF-8 BOM markers in diffs

Environment

• Platform (select one):
• [ ] Anthropic API
• [ ] AWS Bedrock
• [ ] Google Vertex AI
• [x] Other: Claude Code
• Claude CLI version: 1.0.38
• Operating System: MacOS 15.5
• Terminal: Intellij Rider internal terminal

Bug Description

If you have BOM markers at the top of code files (due to sharing code with Windows users)
when Claude shows a diff in the GUI it shows the first line of the file as changed, every time.

The left "Original" side shows a file with type UTF-8 BOM and no changes

The right "Proposed" side shows a file with type UTF-8 and a change adding ZWNBSP to the first character.

Applying the change doesn't change the BOM marker - but this makes the GUI diff hard to use as it always scrolls to the top of the code even if the changes are much further down.

Additional Context

Screenshot:
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