Achievement, mission, and BP monthly mission importers now throw at bootstrap
if any seed row references an event_type that doesn't start with a registered
top-level prefix. Prevents drift: a typo in the seed JSON (or a prefix removed
from code without updating the seed) fails loudly at startup instead of
silently producing counters no emitter writes to.
Verified all 12 top-level prefixes currently in the seed JSON pass validation.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
0f6c8d5e41