fbbc6d4347
Covers: imprint_current base fallback, unload idempotency, load miss → ok=false, ok field presence, respond passthrough for base/empty/unknown IDs, graceful fallback after unload, surface_knowledge and surface_memory_read return-type guarantees, base-scoped knowledge equality, no-annotation invariant for base, empty-ID load rejection, and failed-load state immutability. Syntax follows El constraints: no Bool annotations, no &&/||, no unary !.