platform/ci/check_post_frontmatter.py run on main printed 13 faults across six posts. Four were dated 2026-10-31, five days ahead, so they would have topped the feed early. Four lacked description and tags, and one description ran 180 characters against the 160 limit.
The fix was to date the four posts today (renaming the files to match), add the missing fields, and shorten the long description. The checker now exits 0 on main. The lesson for writers is the one the checker already states: date a post when it is written, and fill in description and tags before pushing.