ToleranceBreachEvent emitted when NPC stress exceeds per-seed threshold. ToleranceBreached marker prevents duplicate events per episode, cleared on recovery. check_tolerance_threshold system runs after update_mood, integrates with mood FSM to push toward Hostile/Anxious. Background-tier NPCs excluded. Unblocks #250 (triangle escalation). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>