ledmatrix-leaderboard's data_fetcher.py calls these two real-CacheManager
methods (src/cache_manager.py:313,817), but MockCacheManager had neither --
update() always hit an AttributeError, caught by a broad except and logged,
so the harness rendered an empty-but-green leaderboard on every test run
without ever exercising real standings data.
Both mocks delegate to the existing get()/set() -- a mock doesn't need the
real strategy's per-data-type max_age/market-hours timing, plugins under
test just need the methods to exist and round-trip whatever was cached.