Windows: plugin marketplace add fails with ENOENT on case-insensitive NTFS rename

Description

/plugin marketplace add fails on Windows when the GitHub org name has mixed case (e.g., MediQuant/marketplace). Claude Code clones the repo to a directory using the original casing (MediQuant-marketplace), then attempts to rename it to lowercase (mediquant-marketplace). On NTFS — which is case-insensitive by default — fs.rename() throws ENOENT because the OS considers the source and target the same path.

Steps to Reproduce

1. On Windows (NTFS, default case-insensitive)
2. Run /plugin marketplace add MediQuant/marketplace (any org with uppercase letters)

Expected Behavior

Marketplace clones and registers successfully.

Actual Behavior

ENOENT: no such file or directory, rename
'C:\Users\<user>\.config\claude-personal\plugins\marketplaces\MediQuant-marketplace'
-> 'C:\Users\<user>\.config\claude-personal\plugins\marketplaces\mediquant-marketplace'

Workaround

Manually clone with a lowercase directory name:

git clone https://github.com/MediQuant/marketplace.git \
  ~/.config/claude-personal/plugins/marketplaces/mediquant-marketplace

Then manually register in known_marketplaces.json.

Suggested Fix

On Windows, either:

• Clone directly to the lowercase target name (skip the rename), or
• Use a two-step rename through a temp directory (e.g., MediQuant-marketplace → tmp-xxx → mediquant-marketplace)

Environment

• Claude Code 2.1.80 (native/winget install)
• Windows 11 Pro (NTFS, default case-insensitive)
• Config directory: ~/.config/claude-personal/