* add scripts/generate_sitemap.sh that discovers all .md files and
produces a standard sitemap.xml in public/
* call the script from build.sh after copying skills
* scope the text/markdown content-type header to /*.md so sitemap.xml
is served as application/xml
Made-with: Cursor
old grader matched by substring (first 40 chars of assertion text),
which silently failed when the grader rephrased assertions. new
approach uses numbered assertions for unambiguous matching.
Co-authored-by: thierrypdamiba <thierrypdamiba@users.noreply.github.com>