feat: 添加中国节假日感知定时功能

- 新增 chinese_holidays 表，通过 timor.tech API 同步节假日数据
- 修正 holiday 字段解读：holiday=true → 休息日，holiday=false → 调休工作日
- 工作日 8:00-22:00 每小时爬取，周末/节假日/夜间自动跳过
- 新增 /api/v1/holidays/sync 和 /api/v1/holidays/today 接口
- 企微菜单新增「同步节假日」按钮，支持手动触发同步

alembic/env.py

@@ -2,6 +2,7 @@ import asyncio
 from alembic import context
 from sqlalchemy.ext.asyncio import create_async_engine
 from app.models.announcement import Base
+from app.models.holiday import ChineseHoliday  # noqa: F401
 from app.config import settings
 
 target_metadata = Base.metadata

alembic/versions/1f59799a5083_add_chinese_holidays_table.py

@@ -0,0 +1,37 @@
+"""add_chinese_holidays_table
+
+Revision ID: 1f59799a5083
+Revises: eed20ee8cc26
+Create Date: 2026-05-09 18:14:31.144256
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = '1f59799a5083'
+down_revision: Union[str, Sequence[str], None] = 'eed20ee8cc26'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Upgrade schema."""
+    op.create_table(
+        'chinese_holidays',
+        sa.Column('date', sa.Date(), nullable=False),
+        sa.Column('is_workday', sa.Boolean(), nullable=False, server_default='true'),
+        sa.Column('year', sa.Integer(), nullable=False),
+        sa.Column('description', sa.String(length=100), nullable=False, server_default=''),
+        sa.PrimaryKeyConstraint('date'),
+    )
+    op.create_index('idx_chinese_holidays_year', 'chinese_holidays', ['year'])
+
+
+def downgrade() -> None:
+    """Downgrade schema."""
+    op.drop_index('idx_chinese_holidays_year', table_name='chinese_holidays')
+    op.drop_table('chinese_holidays')