[BUG] Edit/MultiEdit Tools Return False EPERM Errors

Environment

• Platform (select one):
• [x] Anthropic API
• [ ] AWS Bedrock
• [ ] Google Vertex AI
• [ ] Other: <!-- specify -->
• Claude CLI version: 1.0.44 (Claude Code)
• Operating System: Ubuntu 22.04.5 LTS (running in Multipass VM on Windows host)
• Terminal: xterm-256color

Bug Description

Edit and MultiEdit tools report EPERM: operation not permitted when creating new files, but files are successfully created. The tools show an error message but the operation actually succeeds.

Steps to Reproduce

• Just ask claude to create any file with content

1. Use Edit or MultiEdit tool to create a new file: file_path: /home/ubuntu/projects/my_project/new.txt, edits: [{old_string: "", new_string: "content"}]
2. Tool returns EPERM error: EPERM: operation not permitted, open '/home/ubuntu/projects/my_project/new.txt'
3. Check file system - file is created: -rw-rw-rw- 1 ubuntu ubuntu 0 bytes
4. Use Edit or MultiEdit on same file again - works without error

Expected Behavior

Tools should create files without reporting errors when the operation succeeds.

Actual Behavior

Tools report EPERM: operation not permitted error but successfully create the file.

Additional Context

• Environment: Windows host with Multipass VM Ubuntu 22.04.5 LTS
• Mount configuration: :C:\projects\ubuntu on /home/ubuntu/projects type fuse.sshfs (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other)
• Similar behavior observed with bash commands:

``bash
echo "content" > new.txt # EPERM error, file created empty
touch new.txt # Success
echo "content" > new.txt # Success after touch
``

• This appears to be related to the sshfs mount behavior where file creation triggers a permission error despite succeeding