feat: add migration scripts

backend/migrations/add_general_chat.sql

@@ -0,0 +1,46 @@
+-- 添加通用对话表
+-- 执行日期: 2025-10-11
+-- 用途: 支持无项目/无智能体的纯AI对话功能
+
+-- 1. 创建通用对话表
+CREATE TABLE IF NOT EXISTS general_conversations (
+  id VARCHAR(36) PRIMARY KEY,
+  user_id VARCHAR(36) NOT NULL,
+  title VARCHAR(255) NOT NULL,
+  model_name VARCHAR(50),
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  deleted_at TIMESTAMP,
+  
+  FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+);
+
+-- 2. 创建通用消息表
+CREATE TABLE IF NOT EXISTS general_messages (
+  id VARCHAR(36) PRIMARY KEY,
+  conversation_id VARCHAR(36) NOT NULL,
+  role VARCHAR(20) NOT NULL,
+  content TEXT NOT NULL,
+  model VARCHAR(50),
+  metadata JSONB,
+  tokens INTEGER,
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  
+  FOREIGN KEY (conversation_id) REFERENCES general_conversations(id) ON DELETE CASCADE
+);
+
+-- 3. 创建索引
+CREATE INDEX IF NOT EXISTS idx_general_conversations_user_id ON general_conversations(user_id);
+CREATE INDEX IF NOT EXISTS idx_general_conversations_created_at ON general_conversations(created_at);
+CREATE INDEX IF NOT EXISTS idx_general_conversations_updated_at ON general_conversations(updated_at);
+
+CREATE INDEX IF NOT EXISTS idx_general_messages_conversation_id ON general_messages(conversation_id);
+CREATE INDEX IF NOT EXISTS idx_general_messages_created_at ON general_messages(created_at);
+
+-- 4. 验证表已创建
+SELECT 'general_conversations表已创建' AS status 
+WHERE EXISTS (SELECT 1 FROM information_schema.tables WHERE table_name = 'general_conversations');
+
+SELECT 'general_messages表已创建' AS status 
+WHERE EXISTS (SELECT 1 FROM information_schema.tables WHERE table_name = 'general_messages');
+