feat(assets): align local API with cloud spec

alembic_db/env.py

@@ -8,7 +8,7 @@
 config = context.config
 
 
-from app.database.models import Base
+from app.database.models import Base, NAMING_CONVENTION
 target_metadata = Base.metadata
 
 # other values from the config, defined by the needs of env.py,
@@ -51,7 +51,10 @@ def run_migrations_online() -> None:
 
     with connectable.connect() as connection:
         context.configure(
-            connection=connection, target_metadata=target_metadata
+            connection=connection,
+            target_metadata=target_metadata,
+            render_as_batch=True,
+            naming_convention=NAMING_CONVENTION,
         )
 
         with context.begin_transaction():

alembic_db/versions/0003_add_metadata_job_id.py

@@ -0,0 +1,98 @@
+"""
+Add system_metadata and job_id columns to asset_references.
+Change preview_id FK from assets.id to asset_references.id.
+
+Revision ID: 0003_add_metadata_job_id
+Revises: 0002_merge_to_asset_references
+Create Date: 2026-03-09
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+from app.database.models import NAMING_CONVENTION
+
+revision = "0003_add_metadata_job_id"
+down_revision = "0002_merge_to_asset_references"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    with op.batch_alter_table("asset_references") as batch_op:
+        batch_op.add_column(
+            sa.Column("system_metadata", sa.JSON(), nullable=True)
+        )
+        batch_op.add_column(
+            sa.Column("job_id", sa.String(length=36), nullable=True)
+        )
+
+    # Change preview_id FK from assets.id to asset_references.id (self-ref).
+    # Existing values are asset-content IDs that won't match reference IDs,
+    # so null them out first.
+    op.execute("UPDATE asset_references SET preview_id = NULL WHERE preview_id IS NOT NULL")
+    with op.batch_alter_table(
+        "asset_references", naming_convention=NAMING_CONVENTION
+    ) as batch_op:
+        batch_op.drop_constraint(
+            "fk_asset_references_preview_id_assets", type_="foreignkey"
+        )
+        batch_op.create_foreign_key(
+            "fk_asset_references_preview_id_asset_references",
+            "asset_references",
+            ["preview_id"],
+            ["id"],
+            ondelete="SET NULL",
+        )
+        batch_op.create_index(
+            "ix_asset_references_preview_id", ["preview_id"]
+        )
+
+    # Purge any all-null meta rows before adding the constraint
+    op.execute(
+        "DELETE FROM asset_reference_meta"
+        " WHERE val_str IS NULL AND val_num IS NULL AND val_bool IS NULL AND val_json IS NULL"
+    )
+    with op.batch_alter_table("asset_reference_meta") as batch_op:
+        batch_op.create_check_constraint(
+            "ck_asset_reference_meta_has_value",
+            "val_str IS NOT NULL OR val_num IS NOT NULL OR val_bool IS NOT NULL OR val_json IS NOT NULL",
+        )
+
+
+def downgrade() -> None:
+    # SQLite doesn't reflect CHECK constraints, so we must declare it
+    # explicitly via table_args for the batch recreate to find it.
+    # Use the fully-rendered constraint name to avoid the naming convention
+    # doubling the prefix.
+    with op.batch_alter_table(
+        "asset_reference_meta",
+        table_args=[
+            sa.CheckConstraint(
+                "val_str IS NOT NULL OR val_num IS NOT NULL OR val_bool IS NOT NULL OR val_json IS NOT NULL",
+                name="ck_asset_reference_meta_has_value",
+            ),
+        ],
+    ) as batch_op:
+        batch_op.drop_constraint(
+            "ck_asset_reference_meta_has_value", type_="check"
+        )
+
+    with op.batch_alter_table(
+        "asset_references", naming_convention=NAMING_CONVENTION
+    ) as batch_op:
+        batch_op.drop_index("ix_asset_references_preview_id")
+        batch_op.drop_constraint(
+            "fk_asset_references_preview_id_asset_references", type_="foreignkey"
+        )
+        batch_op.create_foreign_key(
+            "fk_asset_references_preview_id_assets",
+            "assets",
+            ["preview_id"],
+            ["id"],
+            ondelete="SET NULL",
+        )
+
+    with op.batch_alter_table("asset_references") as batch_op:
+        batch_op.drop_column("job_id")
+        batch_op.drop_column("system_metadata")