[Bug] /insights crashes with TypeError ERR_INVALID_ARG_TYPE: path must be string, got array

Bug Description

Running /insights command crashes immediately with:

TypeError [ERR_INVALID_ARG_TYPE]: The "path" property must be of type string, got array

Steps to Reproduce

1. Open a project that is a subdirectory within a larger monorepo, where multiple CLAUDE.md files are loaded (global + parent + project)
2. Run /insights
3. Crash occurs

Likely Cause

The project has 3 CLAUDE.md files loaded:

• ~/.claude/CLAUDE.md (global)
• /path/to/monorepo/CLAUDE.md (parent)
• /path/to/monorepo/sub/project/CLAUDE.md (project)

It appears /insights resolves the CLAUDE.md path as an array of paths instead of a single string, then passes that array to a Node.js fs function that expects a string.

Environment Info

• Claude Code version: 2.1.32
• Platform: macOS (Darwin 25.3.0 arm64)
• Node: v23.11.0
• Terminal: iTerm2

Related

Possibly related to #23138 (different TypeError in /insights on macOS).