type_decay: Exponential decay based on memory type half-life (correction: 180d, preference: 180d, decision: 90d, project: 30d, observation: 14d, general: 60d). Pinned memories are exempt from decay. Memories with more relations decay slower.
When keyword match is strong (>0.3), its weight increases to 0.35 (vector drops to 0.45) for adaptive boosting.
Signal breakdown for debugging/transparency. Includes vector, keyword, recency, base_importance, effective_importance, context_importance, relation_count, and type_decay.