Merge branch 'refactor/backend-architecture' into development

api/alembic/versions/0001_baseline_empty.py

@@ -0,0 +1,27 @@
+"""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