"""baseline_empty

空基线迁移：标记现有数据库 schema 为起点。
对已有数据库执行 alembic stamp head 即可，不做任何 DDL。

Revision ID: 0001_baseline
Revises:
Create Date: 2026-03-16
"""

from typing import Sequence, Union

from alembic import op
import sqlalchemy as sa

revision: str = "0001_baseline"
down_revision: Union[str, None] = None
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    pass


def downgrade() -> None:
    pass