feat(dc/tool-c): Day 2 - Session管理与数据处理完成

核心功能:
- 数据库: 创建dc_tool_c_sessions表 (12字段, 3索引)
- 服务层: SessionService (383行), DataProcessService (303行)
- 控制器: SessionController (300行, 6个API端点)
- 路由: 新增6个Session管理路由
- 测试: 7个API测试全部通过 (100%)

技术亮点:
- 零落盘架构: Excel内存解析, OSS存储
- Session管理: 10分钟过期, 心跳延长机制
- 云原生规范: storage/logger/prisma全平台复用
- 完整测试: 上传/预览/完整数据/删除/心跳

文件清单:
- backend/prisma/schema.prisma (新增DcToolCSession模型)
- backend/prisma/migrations/create_tool_c_session.sql
- backend/scripts/create-tool-c-table.mjs
- backend/src/modules/dc/tool-c/services/ (SessionService, DataProcessService)
- backend/src/modules/dc/tool-c/controllers/SessionController.ts
- backend/src/modules/dc/tool-c/routes/index.ts
- backend/test-tool-c-day2.mjs
- docs/03-业务模块/DC-数据清洗整理/00-工具C当前状态与开发指南.md
- docs/03-业务模块/DC-数据清洗整理/06-开发记录/2025-12-06_工具C_Day2开发完成总结.md

代码统计: ~1900行
测试结果: 7/7 通过 (100%)
云原生规范: 完全符合

backend/scripts/create-tool-c-table.mjs

@@ -0,0 +1,138 @@
+/**
+ * 创建 Tool C Session 表
+ * 
+ * 执行方式：node scripts/create-tool-c-table.mjs
+ */
+
+import { PrismaClient } from '@prisma/client';
+
+const prisma = new PrismaClient();
+
+async function createToolCTable() {
+  console.log('========================================');
+  console.log('开始创建 Tool C Session 表');
+  console.log('========================================\n');
+
+  try {
+    // 1. 检查表是否已存在
+    console.log('[1/4] 检查表是否已存在...');
+    const checkResult = await prisma.$queryRawUnsafe(`
+      SELECT EXISTS (
+        SELECT FROM information_schema.tables 
+        WHERE table_schema = 'dc_schema' 
+        AND table_name = 'dc_tool_c_sessions'
+      ) as exists
+    `);
+    
+    const tableExists = checkResult[0].exists;
+    
+    if (tableExists) {
+      console.log('✅ 表已存在: dc_schema.dc_tool_c_sessions');
+      console.log('\n如需重新创建，请手动执行: DROP TABLE dc_schema.dc_tool_c_sessions CASCADE;\n');
+      return;
+    }
+    
+    console.log('✅ 表不存在，准备创建\n');
+
+    // 2. 创建表
+    console.log('[2/4] 创建表 dc_tool_c_sessions...');
+    await prisma.$executeRawUnsafe(`
+      CREATE TABLE dc_schema.dc_tool_c_sessions (
+        id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+        user_id VARCHAR(255) NOT NULL,
+        file_name VARCHAR(500) NOT NULL,
+        file_key VARCHAR(500) NOT NULL,
+        
+        total_rows INTEGER NOT NULL,
+        total_cols INTEGER NOT NULL,
+        columns JSONB NOT NULL,
+        encoding VARCHAR(50),
+        file_size INTEGER NOT NULL,
+        
+        created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        expires_at TIMESTAMP NOT NULL
+      )
+    `);
+    console.log('✅ 表创建成功\n');
+
+    // 3. 创建索引
+    console.log('[3/4] 创建索引...');
+    await prisma.$executeRawUnsafe(`
+      CREATE INDEX idx_dc_tool_c_sessions_user_id ON dc_schema.dc_tool_c_sessions(user_id)
+    `);
+    await prisma.$executeRawUnsafe(`
+      CREATE INDEX idx_dc_tool_c_sessions_expires_at ON dc_schema.dc_tool_c_sessions(expires_at)
+    `);
+    console.log('✅ 索引创建成功\n');
+
+    // 4. 添加注释
+    console.log('[4/4] 添加表注释...');
+    await prisma.$executeRawUnsafe(`
+      COMMENT ON TABLE dc_schema.dc_tool_c_sessions IS 'Tool C (科研数据编辑器) Session会话表'
+    `);
+    await prisma.$executeRawUnsafe(`
+      COMMENT ON COLUMN dc_schema.dc_tool_c_sessions.file_key IS 'OSS存储路径: dc/tool-c/sessions/{timestamp}-{fileName}'
+    `);
+    await prisma.$executeRawUnsafe(`
+      COMMENT ON COLUMN dc_schema.dc_tool_c_sessions.columns IS '列名数组 ["age", "gender", "diagnosis"]'
+    `);
+    await prisma.$executeRawUnsafe(`
+      COMMENT ON COLUMN dc_schema.dc_tool_c_sessions.expires_at IS '过期时间（创建后10分钟）'
+    `);
+    console.log('✅ 注释添加成功\n');
+
+    // 5. 验证表创建
+    console.log('========================================');
+    console.log('验证表结构');
+    console.log('========================================\n');
+    
+    const columns = await prisma.$queryRawUnsafe(`
+      SELECT column_name, data_type, is_nullable
+      FROM information_schema.columns
+      WHERE table_schema = 'dc_schema' 
+      AND table_name = 'dc_tool_c_sessions'
+      ORDER BY ordinal_position
+    `);
+    
+    console.log('表结构:');
+    console.table(columns);
+    
+    const indexes = await prisma.$queryRawUnsafe(`
+      SELECT indexname, indexdef
+      FROM pg_indexes
+      WHERE schemaname = 'dc_schema' 
+      AND tablename = 'dc_tool_c_sessions'
+    `);
+    
+    console.log('\n索引:');
+    console.table(indexes);
+
+    console.log('\n========================================');
+    console.log('🎉 Tool C Session 表创建成功！');
+    console.log('========================================\n');
+    console.log('表名: dc_schema.dc_tool_c_sessions');
+    console.log(`列数: ${columns.length}`);
+    console.log(`索引数: ${indexes.length}\n`);
+
+  } catch (error) {
+    console.error('\n❌ 创建表失败:', error.message);
+    console.error('\n详细错误:');
+    console.error(error);
+    process.exit(1);
+  } finally {
+    await prisma.$disconnect();
+  }
+}
+
+// 执行
+createToolCTable()
+  .then(() => {
+    console.log('脚本执行完成');
+    process.exit(0);
+  })
+  .catch((error) => {
+    console.error('脚本执行失败:', error);
+    process.exit(1);
+  });
+