feat: add standalone memos

backend/models.py

@@ -239,6 +239,21 @@ class Attachment(Base):
     created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)
 
 
+class Memo(Base):
+    __tablename__ = "memos"
+    __table_args__ = (
+        Index("ix_memos_user_deleted_updated", "user_id", "deleted_at", "updated_at", "id"),
+    )
+    id: Mapped[UUID] = mapped_column(primary_key=True, default=new_id)
+    user_id: Mapped[UUID] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), index=True)
+    title: Mapped[str] = mapped_column(String(200))
+    content: Mapped[str] = mapped_column(Text, default="")
+    version: Mapped[int] = mapped_column(Integer, default=1)
+    created_at: Mapped[datetime] = mapped_column(UTCDateTime(), default=utcnow)
+    updated_at: Mapped[datetime] = mapped_column(UTCDateTime(), default=utcnow)
+    deleted_at: Mapped[datetime | None] = mapped_column(UTCDateTime(), nullable=True)
+
+
 class AuditLog(Base):
     __tablename__ = "audit_logs"
     id: Mapped[UUID] = mapped_column(primary_key=True, default=new_id)