update: workspace lazy load

migrations/versions/3ba4d8489f36_workspace_tree_relative_path_index.py

@@ -0,0 +1,38 @@
+"""Add workspace tree relative_path index.
+
+The ``list_workspace_directories`` endpoint filters by
+``relative_path`` prefixes inside a workspace. A composite index on
+``(workspace_id, relative_path(255))`` avoids scanning all rows for a
+workspace when listing a subdirectory.
+
+Revision ID: 3ba4d8489f36
+Revises: f6a7b8c9d0e1
+Create Date: 2026-08-12
+"""
+
+from collections.abc import Sequence
+
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision: str = "3ba4d8489f36"
+down_revision: str | Sequence[str] | None = "f6a7b8c9d0e1"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    op.create_index(
+        "idx_storage_workspace_relative_path",
+        "storage_objects",
+        [sa.text("`workspace_id`"), sa.text("`relative_path`(255)")],
+        unique=False,
+    )
+
+
+def downgrade() -> None:
+    op.drop_index(
+        "idx_storage_workspace_relative_path",
+        table_name="storage_objects",
+    )