readTomlMeta was dropping any field with a trailing `# comment` (common in
real agents/*.toml). readSkills/readAgents/readRules used bare
isDirectory()/isFile(), which miss symlinked entries per cc-discovery.js's
own documented Dirent quirk — reused its isDirLike/isFileLike instead
(exporting isDirLike from cc-discovery.js, which wasn't previously public).
Also swapped the "never walks outside" test for one that actually exercises
a symlink escape, and dropped the unnecessary isUnder re-export.
nntrivi2001