server: memorySkillFiles.list() and read() do not normalize or validate non-canonical relative paths #3102

Quick question on memorySkillFiles in packages/server/src/ext/skills/files.ts (lines 53-67 on main commit 46d9c99). indexRecord normalizes keys via splitRelativePath(key, 'file path').join('/') when building the dirs and files maps, but memorySkillFiles.list(dir) and memorySkillFiles.read(path) look up dir and path directly without normalizing them through splitRelativePath first (unlike nodeSkillFiles in node.ts).

Because of that, calling list('sub/') or read('./SKILL.md') throws SkillFileNotFoundError, and in read(path) the Object.hasOwn(files, path) check runs before index ?? reindex(), so calling read() before list() bypasses splitRelativePath validation when path matches a raw key on files. Should list() and read() normalize dir and path via splitRelativePath? Happy to open a quick PR with unit tests if you want!