fix(security): potential indexerror when parsing malformed readme (#632)

If a line starting with `*` (app entry) appears before any category header (`### •` or `## –`), `categories[-1]` will raise an `IndexError` because the `categories` list will be empty. A malformed or tampered README.md could cause the CI script to crash with an unhandled exception.

Affected files: ensure_sorted.py

Signed-off-by: Trần Bách <45133811+barttran2k@users.noreply.github.com>

Author: barttran2k

ensure_sorted.py

@@ -79,6 +79,8 @@ def main():
             categories.append(category)
         # This is an app
         elif lines[i].startswith("*"):
+            if not categories:
+                raise RuntimeError("App entry found before any category header")
             # The last category in the categories list is the one we're working on
             category = categories[-1]
             category.add_app(lines[i])