fce5c533fe
NPCs whose home positions are within 4m of each other gain mutual familiarity at baseline 0.5. Stored per NPC as a Dictionary keyed by other npc_id, serialized through NPCStateRecord with backward-compatible fallback for old saves. Household pairs form naturally from the home_positions configuration in main.tscn. Includes save/load round-trip test verifying familiarity persists.