WIP checkpoint: Creator Studio: Asset Import Pipeline — glTF model import backend

backend/alembic/versions/0003_add_gltf_asset_type.py

@@ -0,0 +1,36 @@
+"""add model_gltf value to asset_type enum
+
+Revision ID: 0003_add_gltf_asset_type
+Revises: 0002_add_date_of_birth_to_users
+Create Date: 2025-06-15 00:00:00.000000
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = "0003_add_gltf_asset_type"
+down_revision: Union[str, None] = "0002_add_date_of_birth_to_users"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Add the 'model_gltf' value to the asset_type enum."""
+    # IF NOT EXISTS is supported on PostgreSQL 12+; the project targets
+    # PostgreSQL 16. Adding an enum value and using it in the same
+    # transaction is restricted until commit, but this migration only adds
+    # the value so it is safe inside Alembic's transaction.
+    op.execute("ALTER TYPE asset_type ADD VALUE IF NOT EXISTS 'model_gltf'")
+
+
+def downgrade() -> None:
+    """Remove the 'model_gltf' value from the asset_type enum.
+
+    PostgreSQL does not support dropping an enum value without table scans;
+    this is intentionally a no-op to keep downgrades safe. Re-creating the
+    enum or deleting rows that use this value would be a destructive action
+    better performed manually if ever needed.
+    """
+    pass