Fix review findings in @probo/skills package

Add ISC header to COMPATIBILITY.md, validate Claude marketplace
json, record access-review notes after API success, checksum npm
pack contents, trim dead package.json files entries, and mark
listUsers organization_id as required.

Signed-off-by: Cursor Agent <cursoragent@cursor.com>

Co-authored-by: Bryan FRIMIN <bryan@frimin.fr>

packages/skills/scripts/validate.mjs

@@ -20,6 +20,7 @@ const root = join(dirname(fileURLToPath(import.meta.url)), "..");
 
 const requiredPaths = [
   ".claude-plugin/plugin.json",
+  ".claude-plugin/marketplace.json",
   ".codex-plugin/plugin.json",
   ".agents/plugins/marketplace.json",
   ".mcp.json",