The shader expression registry registers a database from a queued job, and builds its per-key item
lists from the database's lookup without a bounds check. A database destroyed before its job ran,
or a lookup index past its items, left the registry holding pointers that crash it later
(Skate.exe+0x3f7cf33, +0x3f7ceed, +0x20960b in Sentry). The guard skips a registration for a
database already destroyed and points an out-of-range index at a valid item of the same key,
logging each.
