feat: 重构为三所价差异动监控系统

删除 HyperLiquid + 全部交易功能，构建自适应 surge 检测器。
- 新增 surge_detector.go: 每币独立滚动窗口基线，检测三所价差异常飙升
- 新增 SpreadCard/SurgeCard 前端组件
- 保留 momentum/trend/cumulative/trend_filter 扫描功能
- 更新文档和配置以反映新系统

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

db/db.go

@@ -168,6 +168,25 @@ func (d *DB) migrate() error {
 	);
 	CREATE INDEX IF NOT EXISTS idx_trend_signals_coin ON trend_signals(coin);
 	CREATE INDEX IF NOT EXISTS idx_trend_signals_created ON trend_signals(created_at);
+
+	CREATE TABLE IF NOT EXISTS surge_events (
+		id               INTEGER PRIMARY KEY AUTOINCREMENT,
+		coin             TEXT NOT NULL,
+		timestamp        DATETIME NOT NULL,
+		bn_price         REAL,
+		okx_price        REAL,
+		bg_price         REAL,
+		spread_pct       REAL NOT NULL,
+		baseline_pct     REAL,
+		threshold_pct    REAL,
+		ratio            REAL,
+		direction        TEXT NOT NULL,
+		leading_exchange TEXT NOT NULL,
+		mid_price        REAL,
+		created_at       DATETIME DEFAULT CURRENT_TIMESTAMP
+	);
+	CREATE INDEX IF NOT EXISTS idx_surge_events_coin   ON surge_events(coin);
+	CREATE INDEX IF NOT EXISTS idx_surge_events_created ON surge_events(created_at);
 	`
 	_, err := d.Exec(schema)
 	if err != nil {