feat: client endpoints for clients page

models/mixins.py

@@ -23,6 +23,14 @@ class CreatedAtMixin:
     )
 
 
+class LastModifiedAtMixin:
+    last_modified_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        default=lambda: datetime.now(timezone.utc),
+        nullable=False,
+    )
+
+
 class PriceMixin:
     price: Mapped[float] = mapped_column(Numeric(12, 2), comment="Стоимость")