Claude Desktop Filesystem extension ships outdated dist with root path normalization bug

Bug

The Filesystem MCP server extension bundled with Claude Desktop (macOS) ships a compiled dist/path-utils.js that contains a bug already fixed in the source.

The bug

normalizePath("/") returns "" (empty string), causing the server to crash on startup with:

Error accessing directory : Error: ENOENT: no such file or directory, stat ''

Root cause

The installed extension (version 2025.8.21) has the old regex in dist/path-utils.js:

return p.replace(/\/+/g, '/').replace(/\/+$/, '');

This strips the trailing slash from /, producing an empty string.

Already fixed in source

The current TypeScript source (src/filesystem/path-utils.ts) uses a negative lookbehind that correctly preserves /:

return p.replace(/\/+/g, '/').replace(/(?<!^)\/$/, '');

There are even existing tests for this case:

expect(normalizePath('/')).toBe('/');
expect(normalizePath('///')).toBe('/');

Steps to reproduce

1. Install the Filesystem MCP server extension in Claude Desktop (macOS)
2. Add / as an allowed directory
3. Restart Claude Desktop
4. Server crashes immediately — visible in ~/Library/Logs/Claude/mcp-server-Filesystem.log

Expected

The extension should ship a build that includes the root path fix from the source.

Environment

• Claude Desktop on macOS (Darwin 25.3.0, Apple Silicon)
• Extension: ant.dir.ant.anthropic.filesystem
• Installed @modelcontextprotocol/server-filesystem version: 2025.8.21
• Upstream source version: 0.6.3

Compare src/filesystem/path-utils.ts with the bundled dist/path-utils.js, then run the existing normalizePath tests for '/' and '///'. Trace the build and extension release process to determine why the current source was not included; done means the published Claude Desktop extension contains the fixed behavior and the root-directory startup case no longer produces an empty path.