fix: harden economy recovery, shutdown concurrency, world validation, and inventory-loss paths

1 files changed, 9 insertions, 1 deletions

diff --git a/internal/world/mob.go b/internal/world/mob.go
index a794bdd..b004643 100644
--- a/internal/world/mob.go
+++ b/internal/world/mob.go
@@ -665,7 +665,15 @@ func (s *MobStore) SpawnTransient(def *MobDef, cfg *behavior.SpawnMobConfig, roo
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
-	instID := fmt.Sprintf("trigger_%s_%d_%d", cfg.ID, roomID, len(s.instances))
+	instID := ""
+	base := fmt.Sprintf("trigger_%s_%d", cfg.ID, roomID)
+	for n := 0; ; n++ {
+		candidate := fmt.Sprintf("%s_%d", base, n)
+		if _, exists := s.instances[candidate]; !exists {
+			instID = candidate
+			break
+		}
+	}
 	inst := NewMobInstance(def, instID, roomID, nil, 0)
 	inst.Owner = owner
 	inst.OwnerOnly = cfg.OwnerOnly