enrich workspace table information

app/models/workspace.py

@@ -6,11 +6,18 @@ class Workspace(Base, AutoID):
     """工作区表"""
     __tablename__ = "workspaces"
     
+    # --- 基础与个性化 ---
     name = Column(String, nullable=False)
+    slug = Column(String, unique=True, index=True, nullable=False)
+    logo = Column(String, nullable=True)
+    description = Column(String, nullable=True)
+
     # 存储容量上限（单位：字节 Bytes），默认 5GB
     storage_limit = Column(BigInteger, default=5 * 1024 * 1024 * 1024)
+    storage_used = Column(BigInteger, default=0, nullable=False)
 
     created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
 
 
 class WorkspaceMember(Base, AutoID):
@@ -20,9 +27,18 @@ class WorkspaceMember(Base, AutoID):
     workspace_id = Column(String(32), ForeignKey("workspaces.id", ondelete="CASCADE"), index=True)
     user_id = Column(String(32), ForeignKey("users.id", ondelete="CASCADE"), index=True)
 
+    # 允许 user_id 为空，因为被邀请的人可能还没注册系统，我们先记录他的邮箱
+    user_id = Column(String(32), ForeignKey("users.id", ondelete="CASCADE"), nullable=True, index=True)
+    invite_email = Column(String, nullable=True) # 收到邀请的邮箱
+    
+    # 状态：'pending' (等待加入), 'active' (已加入), 'disabled' (已禁用)
+    status = Column(String, default="pending", nullable=False)
     # 角色权限：'owner' (所有者), 'admin' (管理员), 'user' (普通用户)
     role = Column(String, default="user", nullable=False)
     
+    invite_token = Column(String, nullable=True, unique=True)
+    token_expires_at = Column(DateTime(timezone=True), nullable=True)
+
     created_at = Column(DateTime(timezone=True), server_default=func.now())
 
     # 一个用户在一个工作区只能有一条记录