fix: resolve multiple bugs preventing trader creation and deletion

[Professor-Chen]

📝 Description | 描述

English:
This PR fixes multiple bugs that prevented users from creating and deleting AI traders. The issues included database schema mismatches, incorrect field name mappings, and missing React context providers.

中文：
此 PR 修复了阻止用户创建和删除 AI 交易员的多个 bug。问题包括数据库 schema 不匹配、字段名映射错误以及缺失的 React Context Provider。

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🎯 Type of Change | 变更类型

• 🐛 Bug fix | 修复 Bug

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🔗 Related Issues | 相关 Issue

• Fixes trader creation returning 500 error
• Fixes delete trader button not working

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📋 Changes Made | 具体变更

English:

Backend Fixes (Go)

1. Fix time.Time scanning error - SQLite stores datetime as TEXT, now parsing manually instead of relying on driver auto-conversion
2. Fix foreign key mismatch - traders table referenced exchanges(id) but exchanges uses composite primary key (id, user_id). Removed problematic FK constraints
3. Add missing backtestManager field to Server struct
4. Add missing Shutdown method to Server struct
5. Fix NewFuturesTrader call - pass userId parameter
6. Fix UpdateExchange call - pass all required parameters
7. Add migrateTradersTable() - migration function to fix existing databases
8. Fix balance extraction field name mismatch - Binance API returns availableBalance (camelCase) but code looked for available_balance (snake_case)

Frontend Fixes (React)

9. Add missing ConfirmDialogProvider - The delete confirmation dialog required this provider to be wrapped around the App component

中文：

后端修复 (Go)

1. 修复 time.Time 扫描错误 - SQLite 将 datetime 存储为 TEXT，现在手动解析而非依赖驱动自动转换
2. 修复外键不匹配 - traders 表引用 exchanges(id)，但 exchanges 使用复合主键 (id, user_id)，已移除问题外键约束
3. 添加缺失的 backtestManager 字段到 Server 结构体
4. 添加缺失的 Shutdown 方法到 Server 结构体
5. 修复 NewFuturesTrader 调用 - 传递 userId 参数
6. 修复 UpdateExchange 调用 - 传递所有必需参数
7. 添加 migrateTradersTable() - 迁移函数以修复现有数据库
8. 修复余额提取字段名不匹配 - Binance API 返回 availableBalance (驼峰)，但代码查找 available_balance (下划线)

前端修复 (React)

9. 添加缺失的 ConfirmDialogProvider - 删除确认对话框需要此 Provider 包裹 App 组件

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🧪 Testing | 测试

• Tested locally | 本地测试通过
• Verified no existing functionality broke | 确认没有破坏现有功能

Test Results:

• ✅ Create trader with auto balance fetch: Working
• ✅ Delete trader with confirmation dialog: Working
• ✅ Balance correctly extracted from Binance API (17.74 USDT)

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✅ Checklist | 检查清单

Code Quality | 代码质量

• Code follows project style | 代码遵循项目风格
• Self-review completed | 已完成代码自查
• Comments added for complex logic | 已添加必要注释

Documentation | 文档

• Updated relevant documentation | 已更新相关文档

Git

• Commits follow conventional format | 提交遵循 Conventional Commits 格式
• Rebased on latest dev branch | 已 rebase 到最新 dev 分支
• No merge conflicts | 无合并冲突

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📚 Additional Notes | 补充说明

English:
These bugs were present in the original codebase and affected new user onboarding. The fixes are backward compatible and include database migration for existing installations.

中文：
这些 bug 存在于原始代码库中，影响新用户上手体验。修复向后兼容，并包含现有安装的数据库迁移。

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By submitting this PR, I confirm | 提交此 PR，我确认：

• I have read the Contributing Guidelines | 已阅读贡献指南
• I agree to the Code of Conduct | 同意行为准则
• My contribution is licensed under AGPL-3.0 | 贡献遵循 AGPL-3.0 许可证

[github-actions]

🤖 Advisory Check Results

These are advisory checks to help improve code quality. They won't block your PR from being merged.

📋 PR Information

Title Format: ✅ Good - Follows Conventional Commits
PR Size: 🟡 Medium (689 lines: +407 -282)

🔧 Backend Checks

Go Formatting: ⚠️ Needs formatting

Files needing formatting

api/server.go
api/utils_test.go
config/database.go
mcp/client.go
mcp/config.go
mcp/deepseek_client.go
mcp/options.go
mcp/qwen_client.go
mcp/request.go
mcp/request_builder.go

Go Vet: ✅ Good
Tests: ✅ Passed

Fix locally:

go fmt ./...      # Format code
go vet ./...      # Check for issues
go test ./...     # Run tests

⚛️ Frontend Checks

Build & Type Check: ✅ Success

Fix locally:

cd web
npm run build  # Test build (includes type checking)

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📖 Resources

• Contributing Guidelines
• Migration Guide

Questions? Feel free to ask in the comments! 🙏

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These checks are advisory and won't block your PR from being merged. This comment is automatically generated from pr-checks-run.yml.

[tinkle-community]

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