Fix ambiguous SQLAlchemy join for AI generation run relationships

app/models/ai_generation_run.py

@@ -68,5 +68,6 @@ class AIGenerationRun(Base):
     generated_items: Mapped[list["Item"]] = relationship(
         "Item",
         back_populates="generation_run",
+        foreign_keys="Item.generation_run_id",
         lazy="selectin",
     )

app/models/item.py

@@ -223,6 +223,7 @@ class Item(Base):
     generation_run: Mapped[Union["AIGenerationRun", None]] = relationship(
         "AIGenerationRun",
         back_populates="generated_items",
+        foreign_keys=[generation_run_id],
         lazy="selectin",
     )