- Pre-fetch user group IDs in get_*_by_user_id methods across models layer - Pass user_group_ids to has_access to avoid repeated group queries - Reduce query count from 1+N to 1+1 pattern for access control validation - Apply consistent optimization across knowledge, models, notes, prompts, and tools Signed-off-by: Sihyeon Jang <sihyeon.jang@navercorp.com>