split cluster Server into Machine and Server

internal/machine/cluster/machine.go

@@ -0,0 +1,27 @@
+package cluster
+
+import (
+	"crypto/rand"
+	"fmt"
+	"math/big"
+	"uncloud/internal/secret"
+)
+
+// NewMachineID generates a new unique machine ID.
+func NewMachineID() (string, error) {
+	return secret.NewID()
+}
+
+// NewRandomMachineName generates a random machine name in the format "machine-xxxx".
+func NewRandomMachineName() (string, error) {
+	const charset = "abcdefghijklmnopqrstuvwxyz0123456789"
+	suffix := make([]byte, 4)
+	for i := range suffix {
+		randIdx, err := rand.Int(rand.Reader, big.NewInt(int64(len(charset))))
+		if err != nil {
+			return "", fmt.Errorf("get random number: %w", err)
+		}
+		suffix[i] = charset[randIdx.Int64()]
+	}
+	return "machine-" + string(suffix), nil
+}