feat: 添加好友功能并集成 LiteLLM 代理服务

- 新增好友搜索、添加、好友列表功能
- 集成 LiteLLM 代理服务及多模型定价配置
- 更新 iOS CocoaPods 配置
- 更新 .gitignore 和环境变量配置

backend/AGENTS.md

@@ -231,21 +231,23 @@ class AgentType(str, Enum):
 
 Agent loop functionality MUST follow the AG-UI protocol. **Use the `ag-ui` skill** for protocol reference and implementation guidance.
 
-## Multi-Agent Orchestration (CrewAI Framework)
+## Multi-Agent Orchestration (AgentScope Framework)
 
-Multi-agent orchestration MUST use the CrewAI framework. **Use the `crewai` skill** for framework reference and implementation guidance.
+Multi-agent orchestration MUST use the AgentScope framework. **Use the `agentscope-skill`** for framework reference and implementation guidance.
+
+For workflows involving routing, LiteLLM proxy cost audit, or frontend/backend human approval loops, **use the `agentscope-hitl-cost` skill**.
 
 ### Core Principles
 
-- Use CrewAI for orchestrating multiple agents working together
-- Define clear agent roles, tasks, and crews
-- Leverage built-in collaboration and delegation mechanisms
-- Follow CrewAI best practices for agent configuration
+- Use AgentScope for orchestrating multiple agents working together
+- Define clear agent roles, stage responsibilities, and pipeline boundaries
+- Leverage AgentScope built-in workflow and tool middleware mechanisms
+- Follow AgentScope best practices for agent configuration
 
 ### Key Components
 
 - **Agents**: Autonomous units with specific roles and goals
-- **Tasks**: Assignments that agents complete
-- **Crews**: Teams of agents working together
+- **Tasks**: Stage-specific prompts and execution goals
+- **Pipelines**: Ordered orchestration flow between agents
 - **Tools**: Capabilities available to agents
 - **Flows**: Workflow orchestration and state management