feat: migrate from SQLite to PostgreSQL + Redis architecture

Major database migration to modernize the AI trading system:

• **Database Migration**:
  - Add PostgreSQL 15 and Redis 7 services to docker-compose
  - Create comprehensive PostgreSQL schema with proper indexes and triggers
  - Implement DatabaseInterface for multi-database support
  - Add automatic environment-based database selection

• **Infrastructure**:
  - PostgreSQL: ACID transactions, better concurrency, JSON support
  - Redis: High-performance caching layer (prepared for future use)
  - Docker services with health checks and dependency management
  - Persistent volumes for data safety

• **Code Refactoring**:
  - Abstract database operations through DatabaseInterface
  - Implement PostgreSQL-specific operations with proper syntax
  - Update all SQL queries to support both SQLite and PostgreSQL
  - Fix foreign key constraints and data type conversions

• **Migration Tools**:
  - Automated data migration script from SQLite to PostgreSQL
  - Complete backup and restore procedures
  - One-click migration script with validation

• **Compatibility**:
  - Backward compatible with existing SQLite deployments
  - Environment variable driven database selection
  - Preserved all existing functionality and data

🎯 Benefits: Better performance, scalability, and reliability for production deployments

config/database.go

@@ -13,6 +13,7 @@ import (
 	"strings"
 	"time"
 
+	_ "github.com/lib/pq"
 	_ "github.com/mattn/go-sqlite3"
 )
 
@@ -21,8 +22,53 @@ type Database struct {
 	db *sql.DB
 }
 
+// DatabaseInterface 数据库接口
+type DatabaseInterface interface {
+	CreateUser(user *User) error
+	EnsureAdminUser() error
+	GetUserByEmail(email string) (*User, error)
+	GetUserByID(userID string) (*User, error)
+	GetAllUsers() ([]string, error)
+	UpdateUserOTPVerified(userID string, verified bool) error
+	GetAIModels(userID string) ([]*AIModelConfig, error)
+	UpdateAIModel(userID, id string, enabled bool, apiKey, customAPIURL, customModelName string) error
+	GetExchanges(userID string) ([]*ExchangeConfig, error)
+	UpdateExchange(userID, id string, enabled bool, apiKey, secretKey string, testnet bool, hyperliquidWalletAddr, asterUser, asterSigner, asterPrivateKey string) error
+	CreateAIModel(userID, id, name, provider string, enabled bool, apiKey, customAPIURL string) error
+	CreateExchange(userID, id, name, typ string, enabled bool, apiKey, secretKey string, testnet bool, hyperliquidWalletAddr, asterUser, asterSigner, asterPrivateKey string) error
+	CreateTrader(trader *TraderRecord) error
+	GetTraders(userID string) ([]*TraderRecord, error)
+	UpdateTraderStatus(userID, id string, isRunning bool) error
+	UpdateTrader(trader *TraderRecord) error
+	UpdateTraderCustomPrompt(userID, id string, customPrompt string, overrideBase bool) error
+	DeleteTrader(userID, id string) error
+	GetTraderConfig(userID, traderID string) (*TraderRecord, *AIModelConfig, *ExchangeConfig, error)
+	GetSystemConfig(key string) (string, error)
+	SetSystemConfig(key, value string) error
+	CreateUserSignalSource(userID, coinPoolURL, oiTopURL string) error
+	GetUserSignalSource(userID string) (*UserSignalSource, error)
+	UpdateUserSignalSource(userID, coinPoolURL, oiTopURL string) error
+	GetCustomCoins() []string
+	LoadBetaCodesFromFile(filePath string) error
+	ValidateBetaCode(code string) (bool, error)
+	UseBetaCode(code, userEmail string) error
+	GetBetaCodeStats() (total, used int, err error)
+	Close() error
+}
+
 // NewDatabase 创建配置数据库
-func NewDatabase(dbPath string) (*Database, error) {
+func NewDatabase(dbPath string) (DatabaseInterface, error) {
+	// 检查是否启用PostgreSQL
+	if os.Getenv("POSTGRES_HOST") != "" {
+		// 使用PostgreSQL
+		pgDB, err := NewPostgreSQLDatabase()
+		if err != nil {
+			return nil, fmt.Errorf("创建PostgreSQL数据库失败: %w", err)
+		}
+		return pgDB, nil
+	}
+
+	// 使用SQLite（兼容模式）
 	db, err := sql.Open("sqlite3", dbPath)
 	if err != nil {
 		return nil, fmt.Errorf("打开数据库失败: %w", err)