builtinSkillTextAt function
The built-in skill text at path (builtin://skills/<name>/SKILL.md),
or null when path is not a built-in skill path. Read-tool hosts call
this before touching the filesystem.
Implementation
String? builtinSkillTextAt(String path) {
if (!path.startsWith(builtinSkillPathPrefix)) return null;
final rest = path.substring(builtinSkillPathPrefix.length);
final slash = rest.indexOf('/');
if (slash < 0 || rest.substring(slash) != '/SKILL.md') return null;
final name = rest.substring(0, slash);
for (final skill in builtinSkills()) {
if (skill.name == name) return skill.embeddedText;
}
return null;
}