feat: 导入 MemRelay 初始源码

backend/migrations/versions/20260802_0004_file_directories.py

@@ -0,0 +1,25 @@
+"""Add directory records to the file catalog."""
+
+from collections.abc import Sequence
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "20260802_0004"
+down_revision: str | Sequence[str] | None = "20260802_0003"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    with op.batch_alter_table("file_records") as batch:
+        batch.add_column(
+            sa.Column("is_directory", sa.Boolean(), nullable=False, server_default=sa.false())
+        )
+        batch.create_index("ix_file_records_is_directory", ["is_directory"])
+
+
+def downgrade() -> None:
+    with op.batch_alter_table("file_records") as batch:
+        batch.drop_index("ix_file_records_is_directory")
+        batch.drop_column("is_directory")