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/task.py

@@ -1,7 +1,7 @@
 """
 任务模型 — Goal 拆解的子任务
 """
-from sqlalchemy import Column, String, Text, Integer, DateTime, JSON, Boolean, ForeignKey, func
+from sqlalchemy import Column, String, Text, Integer, DateTime, JSON, Boolean, ForeignKey, Index, func
 from sqlalchemy.dialects.mysql import CHAR
 from sqlalchemy.orm import relationship
 from app.core.database import Base
@@ -25,9 +25,13 @@ class Task(Base):
     # 任务编排配置
     task_config = Column(JSON, comment="编排配置: {orchestration_mode, agents:[], workflow_id, input_data}")
 
-    # 依赖关系
+    # 依赖关系（参考 Claude Code task_system 设计）
     parent_task_id = Column(CHAR(36), ForeignKey("tasks.id"), nullable=True, comment="父任务ID")
-    depends_on = Column(JSON, default=list, comment="前置依赖任务ID列表")
+    depends_on = Column(JSON, default=list, comment="前置依赖任务ID列表 (blockedBy)")
+    blocks = Column(JSON, default=list, comment="被此任务阻塞的任务ID列表")
+
+    # 认领机制（参考 Claude Code claimTask）
+    owner = Column(String(200), nullable=True, comment="认领此任务的 Agent 标识 (区别于 assigned_agent_id)")
 
     # 执行结果
     result = Column(JSON, comment="执行输出结果")
@@ -42,6 +46,7 @@ class Task(Base):
     requires_approval = Column(Boolean, default=False, comment="是否需要人工审批")
     approver_id = Column(CHAR(36), ForeignKey("users.id"), nullable=True, comment="审批人ID")
     approval_status = Column(String(20), comment="审批状态: pending/approved/rejected")
+    workspace_id = Column(CHAR(36), ForeignKey("workspaces.id"), nullable=True, comment="所属工作区ID")
 
     # 时间
     started_at = Column(DateTime, comment="开始时间")