deps: add go-playground/validator/v10 and update crypto deps

Ultraworked with Sisyphus (https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

backend/internal/validators/validators.go

@@ -1,9 +1,25 @@
 package validators
 
 import (
+	"github.com/go-playground/validator/v10"
+	"reflect"
 	"regexp"
+	"strings"
 )
 
+var Validate *validator.Validate
+
+func init() {
+	Validate = validator.New()
+	Validate.RegisterTagNameFunc(func(fld reflect.StructField) string {
+		name := strings.SplitN(fld.Tag.Get("json"), ",", 2)[0]
+		if name == "-" {
+			return ""
+		}
+		return name
+	})
+}
+
 // ID format: 12-character hexadecimal string (from gen_random_bytes(6) encoded as hex)
 var validIDRegex = regexp.MustCompile(`^[0-9a-f]{12}$`)