init: hgmj server initial commit

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

common/maths/data.go

@@ -0,0 +1,23 @@
+package maths
+
+type Float64Data []float64
+
+func (f Float64Data) Get(i int) float64 { return f[i] }
+
+func (f Float64Data) Len() int { return len(f) }
+
+func (f Float64Data) Sum() (float64, error) { return Sum(f) }
+
+func (f Float64Data) Mean() (float64, error) { return Mean(f) }
+
+func (f Float64Data) Correlation(d Float64Data) (float64, error) {
+	return Correlation(f, d)
+}
+
+func (f Float64Data) AutoCorrelation(lags int) (float64, error) {
+	return AutoCorrelation(f, lags)
+}
+
+func (f Float64Data) Pearson(d Float64Data) (float64, error) {
+	return Pearson(f, d)
+}