fix: 删除零成交误判逻辑 + 各种稳定性修复

- 删除: Bitget GetTradeFee 零成交检查（PlaceMarketOrder 成功即成交）
- 修复: GetTradeFee 加 1s 延迟 + 查不到返回 0（用配置估算费兜底）
- 修复: HL InitExchange 在 NewTrader 中提前调用，避免 szDecimals 延迟
- 修复: close_failed 30 次重试上限，超限标记 failed 并清理
- 修复: DB 恢复时校验 Legs 完整性，跳过非法记录
- 修复: checkScaleIn/checkExit nil guard 防 panic
- 修复: config.go 参数调整（手续费、阈值等）
- 移除: scanner.go 中 MEW/USTC 等低流动性币对
- 添加: 更详细的下单日志（szStr、amountUSD、price）
- 添加: bin/ 到 .gitignore

scanner.go

@@ -28,7 +28,6 @@ var TrackedCoins = []TrackedCoin{
 	{Name: "AAVE", BN: "", BG: "AAVEUSDT", HL: "AAVE"},
 	{Name: "ACE", BN: "", BG: "ACEUSDT", HL: "ACE"},
 	{Name: "ADA", BN: "", BG: "ADAUSDT", HL: "ADA"},
-	{Name: "AERO", BN: "", BG: "AEROUSDT", HL: "AERO"},
 	{Name: "AIXBT", BN: "", BG: "AIXBTUSDT", HL: "AIXBT"},
 	{Name: "ALGO", BN: "", BG: "ALGOUSDT", HL: "ALGO"},
 	{Name: "ALT", BN: "", BG: "ALTUSDT", HL: "ALT"},
@@ -117,7 +116,6 @@ var TrackedCoins = []TrackedCoin{
 	{Name: "MEME", BN: "", BG: "MEMEUSDT", HL: "MEME"},
 	{Name: "MERL", BN: "", BG: "MERLUSDT", HL: "MERL"},
 	{Name: "MET", BN: "", BG: "METUSDT", HL: "MET"},
-	{Name: "MEW", BN: "", BG: "MEWUSDT", HL: "MEW"},
 	{Name: "MINA", BN: "", BG: "MINAUSDT", HL: "MINA"},
 	{Name: "MON", BN: "", BG: "MONUSDT", HL: "MON"},
 	{Name: "MOODENG", BN: "", BG: "MOODENGUSDT", HL: "MOODENG"},
@@ -176,7 +174,6 @@ var TrackedCoins = []TrackedCoin{
 	{Name: "TURBO", BN: "", BG: "TURBOUSDT", HL: "TURBO"},
 	{Name: "UMA", BN: "", BG: "UMAUSDT", HL: "UMA"},
 	{Name: "UNI", BN: "", BG: "UNIUSDT", HL: "UNI"},
-	{Name: "USTC", BN: "", BG: "USTCUSDT", HL: "USTC"},
 	{Name: "USUAL", BN: "", BG: "USUALUSDT", HL: "USUAL"},
 	{Name: "VIRTUAL", BN: "", BG: "VIRTUALUSDT", HL: "VIRTUAL"},
 	{Name: "VVV", BN: "", BG: "VVVUSDT", HL: "VVV"},