init: hgmj server initial commit

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

common/maths/min.go

@@ -0,0 +1,17 @@
+package maths
+
+import "math"
+
+func Min(input Float64Data) (min float64, err error) {
+	l := input.Len()
+	if l == 0 {
+		return math.NaN(), EmptyInputErr
+	}
+	min = input.Get(0)
+	for i := 1; i < l; i++ {
+		if input.Get(i) < min {
+			min = input.Get(i)
+		}
+	}
+	return min, nil
+}