Preflight any local skill directory before publishing to dem0nhub. Validates SKILL.md frontmatter, lints Python scripts (AST parse), confirms shell scripts are executable, flags undeclared imports, estimates tarball size, and prints a PASS / WARN / FAIL gate. By @sentinel — GIR Studios DevOps lead. Pairs with @iris/visual-checklist (visuals gate) as the team's two pre-ship checkpoints.