feat: 添加OKX行情接入+趋势检测+累积变动系统+界面重构

- 新增OKX WebSocket行情连接器，扩展4交易所价格监控
- 新增z-score趋势检测引擎(TrendDetector)，识别价格异动/趋势启动
- 新增累积变动跟踪(CumulativeTracker)，基于1min/5min多交易所共识
- 趋势事件和累积变动事件持久化到SQLite
- 新增Binance/OKX动量检测字段，扩展前端动量卡片至15列
- 迁移至macOS(darwin-arm64)，更新前端依赖
- Dashboard网格重构：非交易卡片置顶，交易卡片置底
- TrackedCoin添加OK字段，添加ExBinance/ExOKX常量
- 前端新增趋势检测卡片、趋势历史卡片、累积变动卡片

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

trend_test.go

@@ -0,0 +1,119 @@
+package main
+
+import (
+	"math"
+	"testing"
+)
+
+func TestMeanStdDev(t *testing.T) {
+	changes := []exchangeChange{
+		{name: "A", change: 0.1},
+		{name: "B", change: 0.2},
+		{name: "C", change: 0.3},
+		{name: "D", change: 0.4},
+	}
+	mean, std := meanStdDev(changes)
+
+	if math.Abs(mean-0.25) > 0.001 {
+		t.Errorf("mean = %.4f, want 0.2500", mean)
+	}
+	if math.Abs(std-0.1118) > 0.01 {
+		t.Errorf("std = %.4f, want ~0.1118", std)
+	}
+}
+
+func TestMeanStdDevSingleValue(t *testing.T) {
+	changes := []exchangeChange{
+		{name: "A", change: 0.1},
+	}
+	mean, std := meanStdDev(changes)
+	if mean != 0.1 {
+		t.Errorf("mean = %.4f, want 0.1000", mean)
+	}
+	if std != 0 {
+		t.Errorf("std = %.4f, want 0.0000", std)
+	}
+}
+
+func TestMeanStdDevZeroValues(t *testing.T) {
+	changes := []exchangeChange{
+		{name: "A", change: 0},
+		{name: "B", change: 0},
+	}
+	mean, std := meanStdDev(changes)
+	if mean != 0 {
+		t.Errorf("mean = %.4f, want 0.0000", mean)
+	}
+	if std != 0 {
+		t.Errorf("std = %.4f, want 0.0000", std)
+	}
+}
+
+func TestMeanStdDevEmpty(t *testing.T) {
+	mean, std := meanStdDev(nil)
+	if mean != 0 || std != 0 {
+		t.Errorf("expected 0,0 for empty input, got %.4f, %.4f", mean, std)
+	}
+}
+
+func TestZScoreCalculation(t *testing.T) {
+	// One exchange strongly diverging from the others
+	// Three exchanges nearly flat, one moves 1.5%
+	changes := []exchangeChange{
+		{name: "BG", change: 0.01},
+		{name: "HL", change: 0.01},
+		{name: "BN", change: 0.02},
+		{name: "OK", change: 1.50}, // anomalous!
+	}
+	_, std := meanStdDev(changes)
+	maxAbs := 1.50
+	zScore := maxAbs / std
+
+	if zScore < 2.0 {
+		t.Errorf("z-score = %.2f, expected > 2.0 for divergent exchange", zScore)
+	}
+	t.Logf("Divergent exchange (1 of 4): z-score = %.2f (std = %.4f)", zScore, std)
+}
+
+func TestCoordinatedMovement(t *testing.T) {
+	// All exchanges moving together = also a trend (consensus, not anomaly)
+	changes := []exchangeChange{
+		{name: "BG", change: 0.05},
+		{name: "HL", change: 0.06},
+		{name: "BN", change: 0.04},
+		{name: "OK", change: 0.07},
+	}
+	_, std := meanStdDev(changes)
+	maxAbs := 0.07
+	zScore := maxAbs / std
+
+	// Tight cluster → std is small, z-score is high → valid trend signal
+	t.Logf("Co-movement: z-score = %.2f (std = %.4f) — high z-score + 4/4 agreement = trend", zScore, std)
+}
+
+func TestTrendDetectorConfigure(t *testing.T) {
+	td := NewTrendDetector(nil)
+	if td.anomalyMul != 3.0 {
+		t.Errorf("default anomalyMul = %.1f, want 3.0", td.anomalyMul)
+	}
+	if td.confirmTicks != 3 {
+		t.Errorf("default confirmTicks = %d, want 3", td.confirmTicks)
+	}
+
+	td.Configure(300, 2.5, 2, 30000)
+	if td.anomalyMul != 2.5 {
+		t.Errorf("anomalyMul after configure = %.1f, want 2.5", td.anomalyMul)
+	}
+	if td.confirmTicks != 2 {
+		t.Errorf("confirmTicks after configure = %d, want 2", td.confirmTicks)
+	}
+}
+
+func TestTrendDetectorEmptyConfigure(t *testing.T) {
+	td := NewTrendDetector(nil)
+	// Passing zeros should keep defaults
+	td.Configure(0, 0, 0, 0)
+	if td.anomalyMul != 3.0 {
+		t.Errorf("anomalyMul = %.1f, expected default 3.0", td.anomalyMul)
+	}
+}