Problem: lua typecheck flagged missing start_time field on ContestSummary;
ty flagged BeautifulSoup Tag/NavigableString union on csrf_input.get(),
a 3-tuple unpack where _extract_problem_info now returns 4 values in
cses.py, and an untyped list assignment in usaco.py.
Solution: add start_time? to ContestSummary LuaDoc, guard csrf_input
with hasattr check and type: ignore, unpack precision from
_extract_problem_info in cses.py callers, and use cast() in usaco.py.
Barrett Ruth
de5a20c567