"""initial baseline

Revision ID: 0001_initial
Revises:
Create Date: 2026-05-31 00:00:00

这是 Alembic 接入时的占位 baseline。

- 全新部署：``alembic upgrade head`` 会跑过这条 no-op，
  然后由后续 ``alembic revision --autogenerate`` 生成真正的建表脚本，
  或在首次部署时由应用 ``Base.metadata.create_all`` 直接建表，再 ``alembic stamp head``。
- 已有数据库：直接 ``alembic stamp 0001_initial`` 标定基线，再做后续 autogenerate。
"""

from typing import Sequence, Union


revision: str = "0001_initial"
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