init: hgmj server initial commit

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

models/v/usermod/error.go

@@ -0,0 +1,13 @@
+package usermod
+
+import "fmt"
+
+// MobileHasBindError 手机已被绑定
+type MobileHasBindError struct {
+	UID             uint64
+	DuplicateMobile string
+}
+
+func (m MobileHasBindError) Error() string {
+	return fmt.Sprintf("UID:%d Don't use Duplicate Mobile:%s \n", m.UID, m.DuplicateMobile)
+}