feat:1.数据库存储功能添加（初版）2.后端REST API版本代码清理

backend/db/schema.sql

@@ -0,0 +1,70 @@
+-- AgentCoord 数据库表结构
+-- 基于 DATABASE_DESIGN.md 设计
+-- 执行方式: psql -U postgres -d agentcoord -f schema.sql
+
+-- =============================================================================
+-- 表1: multi_agent_tasks (多智能体任务记录)
+-- 状态枚举: pending/planning/generating/executing/completed/failed
+-- =============================================================================
+CREATE TABLE IF NOT EXISTS multi_agent_tasks (
+    task_id VARCHAR(64) PRIMARY KEY,
+    user_id VARCHAR(64) NOT NULL,
+    query TEXT NOT NULL,
+    agents_info JSONB NOT NULL,
+    task_outline JSONB,
+    assigned_agents JSONB,
+    agent_scores JSONB,
+    result JSONB,
+    status VARCHAR(20) DEFAULT 'pending',
+    execution_count INTEGER DEFAULT 0,
+    generation_id VARCHAR(64),
+    execution_id VARCHAR(64),
+    rehearsal_log JSONB,
+    branches JSONB,                    -- 任务大纲探索分支数据
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
+);
+
+-- 索引
+CREATE INDEX IF NOT EXISTS idx_multi_agent_tasks_user_id ON multi_agent_tasks(user_id);
+CREATE INDEX IF NOT EXISTS idx_multi_agent_tasks_created_at ON multi_agent_tasks(created_at DESC);
+CREATE INDEX IF NOT EXISTS idx_multi_agent_tasks_status ON multi_agent_tasks(status);
+CREATE INDEX IF NOT EXISTS idx_multi_agent_tasks_generation_id ON multi_agent_tasks(generation_id);
+CREATE INDEX IF NOT EXISTS idx_multi_agent_tasks_execution_id ON multi_agent_tasks(execution_id);
+
+-- =============================================================================
+-- 表2: user_agents (用户保存的智能体配置) - 可选表
+-- =============================================================================
+CREATE TABLE IF NOT EXISTS user_agents (
+    id VARCHAR(64) PRIMARY KEY,
+    user_id VARCHAR(64) NOT NULL,
+    agent_name VARCHAR(100) NOT NULL,
+    agent_config JSONB NOT NULL,
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE INDEX IF NOT EXISTS idx_user_agents_user_id ON user_agents(user_id);
+
+-- =============================================================================
+-- 更新时间触发器函数
+-- =============================================================================
+CREATE OR REPLACE FUNCTION update_updated_at_column()
+RETURNS TRIGGER AS $$
+BEGIN
+    NEW.updated_at = CURRENT_TIMESTAMP;
+    RETURN NEW;
+END;
+$$ language 'plpgsql';
+
+-- 为 multi_agent_tasks 表创建触发器
+CREATE TRIGGER update_multi_agent_tasks_updated_at
+    BEFORE UPDATE ON multi_agent_tasks
+    FOR EACH ROW
+    EXECUTE FUNCTION update_updated_at_column();
+
+DO $$
+BEGIN
+    RAISE NOTICE '✅ PostgreSQL 数据库表结构创建完成！';
+    RAISE NOTICE '表: multi_agent_tasks (多智能体任务记录)';
+    RAISE NOTICE '表: user_agents (用户智能体配置)';
+END $$;