fix: delete agent 500 error + dynamic personality + deployment guide

- Fix delete agent 500: clean up FK records (agent_llm_logs, permissions,
  schedules, executions, team_members) and unbind goals/tasks before delete
- Remove hardcoded personality templates in Android, replace with dynamic
  system prompt generation from name + description
- Set promptSectionsEnabled=false to bypass PromptComposer for personality
- Add Tencent Cloud Linux deployment guide (Docker Compose)
- Accumulated backend service updates, frontend UI fixes, Android app changes

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/models/workspace.py

@@ -0,0 +1,61 @@
+"""
+工作区 (Workspace) 模型 — 多租户数据隔离
+"""
+from sqlalchemy import Column, String, Text, Integer, DateTime, JSON, ForeignKey, Index, func
+from sqlalchemy.dialects.mysql import CHAR
+from sqlalchemy.orm import relationship
+from app.core.database import Base
+import uuid
+
+
+class Workspace(Base):
+    """工作区/租户表"""
+    __tablename__ = "workspaces"
+
+    id = Column(CHAR(36), primary_key=True, default=lambda: str(uuid.uuid4()), comment="工作区ID")
+    name = Column(String(100), nullable=False, comment="工作区名称")
+    description = Column(Text, comment="描述")
+    avatar = Column(String(500), nullable=True, comment="Logo URL")
+    is_default = Column(Integer, default=0, comment="是否为默认工作区: 0=否 1=是")
+    owner_id = Column(CHAR(36), ForeignKey("users.id"), nullable=False, comment="所有者ID")
+    max_members = Column(Integer, default=50, comment="最大成员数")
+    settings = Column(JSON, nullable=True, comment="工作区设置")
+    status = Column(String(20), default="active", comment="状态: active/disabled/deleted")
+    created_at = Column(DateTime, default=func.now(), comment="创建时间")
+    updated_at = Column(DateTime, default=func.now(), onupdate=func.now(), comment="更新时间")
+
+    owner = relationship("User", backref="owned_workspaces")
+    memberships = relationship("WorkspaceMembership", back_populates="workspace", cascade="all, delete-orphan")
+
+    def to_dict(self):
+        return {
+            "id": self.id,
+            "name": self.name,
+            "description": self.description,
+            "avatar": self.avatar,
+            "is_default": bool(self.is_default),
+            "owner_id": self.owner_id,
+            "max_members": self.max_members,
+            "settings": self.settings,
+            "status": self.status,
+            "created_at": self.created_at.isoformat() if self.created_at else None,
+            "updated_at": self.updated_at.isoformat() if self.updated_at else None,
+        }
+
+
+class WorkspaceMembership(Base):
+    """工作区成员关联表"""
+    __tablename__ = "workspace_memberships"
+
+    id = Column(CHAR(36), primary_key=True, default=lambda: str(uuid.uuid4()), comment="关联ID")
+    workspace_id = Column(CHAR(36), ForeignKey("workspaces.id", ondelete="CASCADE"), nullable=False, comment="工作区ID")
+    user_id = Column(CHAR(36), ForeignKey("users.id", ondelete="CASCADE"), nullable=False, comment="用户ID")
+    role = Column(String(20), nullable=False, default="member", comment="角色: admin/member")
+    joined_at = Column(DateTime, default=func.now(), comment="加入时间")
+
+    workspace = relationship("Workspace", back_populates="memberships")
+    user = relationship("User", backref="workspace_memberships")
+
+    __table_args__ = (
+        Index("ix_ws_membership_workspace_user", "workspace_id", "user_id", unique=True),
+    )