feat: 初始提交

backend/app/models/admin_setting.py

@@ -0,0 +1,13 @@
+from sqlalchemy import String, Text
+from sqlalchemy.orm import Mapped, mapped_column
+
+from ..db.base import Base
+
+
+class AdminSetting(Base):
+    """后台配置项，采用简单的 KV 结构。"""
+
+    __tablename__ = "admin_settings"
+
+    key: Mapped[str] = mapped_column(String(64), primary_key=True)
+    value: Mapped[str] = mapped_column(Text, nullable=False)