update alembic migrations

alembic/versions/005_unique_images_constraint.py

@@ -0,0 +1,33 @@
+"""add unique constraint on images(car_id, fullres_image)
+
+Revision ID: 005
+Revises: 004_widen_string_columns
+Create Date: 2026-04-16
+"""
+from alembic import op
+
+revision = "005_unique_images_constraint"
+down_revision = "004_widen_string_columns"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # Удаляем дубли через CTE + ROW_NUMBER (быстрее чем NOT IN subquery)
+    op.execute("""
+        WITH dupes AS (
+            SELECT id,
+                   ROW_NUMBER() OVER (PARTITION BY car_id, fullres_image ORDER BY id) AS rn
+            FROM images
+        )
+        DELETE FROM images WHERE id IN (SELECT id FROM dupes WHERE rn > 1)
+    """)
+    op.create_unique_constraint(
+        "uq_images_car_id_fullres",
+        "images",
+        ["car_id", "fullres_image"],
+    )
+
+
+def downgrade() -> None:
+    op.drop_constraint("uq_images_car_id_fullres", "images", type_="unique")