fix: eliminate Node.js path dependencies in client-side code

[rsp2k]

What's the problem?

In dev mode, the console fills up with warnings like:

Module "path" has been externalized for browser compatibility. Cannot access "path.sep" in client code.

The graph renders briefly then disappears. Root cause: preprocess-sitemap.ts imports micromatch, which pulls in picomatch → node:path. Browsers don't have node:path, so Vite stubs it out and things break.

The fix

Created sitemap/browser-utils.ts with pure JS alternatives:

• isGlobMatch() / firstMatchingPatternBrowser() - regex-based glob matching (replaces micromatch for client code)
• joinUrlPath() - string-based path joining

Updated all client-side files to import from browser-utils.ts. Server-side Astro frontmatter can still use the full micromatch via util.ts.

Tested

• Dev mode: clean console, graph works
• Prod build + preview: works fine

No breaking changes - just swapping out the internals.

[Fevol]

node:path can be used in the frontmatter component of .astro files without issue, and while I think it isn't a terrible idea to replace micromatch completely for the client, the current implementation does not fully implement the full syntax that picomatch exposes, creating a breaking change for users. I believe solving the dependency issue is a better solution in the long-term.

EDIT: Sorry, I misread the first part of your message. After some more investigation, it is sensible to split up the functionality into browser-utils. Also, instead of fully replacing micromatch on the client-side, I decided that the easiest solution would be to use picomatch. This does sadly come with a regression with the bracket expansion functionality that micromatch offers. While not ideal, I currently do not see a better solution.