Feat: Add configurable leverage settings for BTC/ETH and altcoins (v2.0.3)

- Add LeverageConfig struct with btc_eth_leverage and altcoin_leverage fields
- Set default leverage to 5x (safe for Binance subaccounts)
- Add validation warnings for leverage >5x (subaccount restrictions)
- Update config.json.example with leverage configuration

Breaking changes:
- None (backward compatible with default 5x leverage)

Migration:
- Existing configs will auto-default to 5x leverage (safe)
- Main accounts can increase to 20x (altcoins) or 50x (BTC/ETH) in config.json
- Subaccounts must keep leverage ≤5x to avoid trade failures

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: tinkle-community <tinklefund@gmail.com>

config.json.example

@@ -13,6 +13,10 @@
       "scan_interval_minutes": 3
     }
   ],
+  "leverage": {
+    "btc_eth_leverage": 5,
+    "altcoin_leverage": 5
+  },
   "use_default_coins": true,
   "coin_pool_api_url": "",
   "oi_top_api_url": "",

config/config.go

@@ -20,6 +20,12 @@ type TraderConfig struct {
 	ScanIntervalMinutes int     `json:"scan_interval_minutes"`
 }
 
+// LeverageConfig 杠杆配置
+type LeverageConfig struct {
+	BTCETHLeverage  int `json:"btc_eth_leverage"`  // BTC和ETH的杠杆倍数（主账户建议5-50，子账户≤5）
+	AltcoinLeverage int `json:"altcoin_leverage"`  // 山寨币的杠杆倍数（主账户建议5-20，子账户≤5）
+}
+
 // Config 总配置
 type Config struct {
 	Traders            []TraderConfig `json:"traders"`
@@ -30,6 +36,7 @@ type Config struct {
 	MaxDailyLoss       float64        `json:"max_daily_loss"`
 	MaxDrawdown        float64        `json:"max_drawdown"`
 	StopTradingMinutes int            `json:"stop_trading_minutes"`
+	Leverage           LeverageConfig `json:"leverage"` // 杠杆配置
 }
 
 // LoadConfig 从文件加载配置
@@ -100,6 +107,20 @@ func (c *Config) Validate() error {
 		c.APIServerPort = 8080 // 默认8080端口
 	}
 
+	// 设置杠杆默认值（适配币安子账户限制，最大5倍）
+	if c.Leverage.BTCETHLeverage <= 0 {
+		c.Leverage.BTCETHLeverage = 5 // 默认5倍（安全值，适配子账户）
+	}
+	if c.Leverage.BTCETHLeverage > 5 {
+		fmt.Printf("⚠️  警告: BTC/ETH杠杆设置为%dx，如果使用子账户可能会失败（子账户限制≤5x）\n", c.Leverage.BTCETHLeverage)
+	}
+	if c.Leverage.AltcoinLeverage <= 0 {
+		c.Leverage.AltcoinLeverage = 5 // 默认5倍（安全值，适配子账户）
+	}
+	if c.Leverage.AltcoinLeverage > 5 {
+		fmt.Printf("⚠️  警告: 山寨币杠杆设置为%dx，如果使用子账户可能会失败（子账户限制≤5x）\n", c.Leverage.AltcoinLeverage)
+	}
+
 	return nil
 }