refactor(core): разбить client.go (1678 строк) на 15 мелких модулей по зонам ответственности

provider/internal/core/uuid.go

@@ -0,0 +1,29 @@
+package core
+
+import "strings"
+
+// ===== UUID-утилиты =====
+
+func isUUIDLike(value string) bool {
+	trimmed := strings.TrimSpace(value)
+	if len(trimmed) != 36 {
+		return false
+	}
+	for i, r := range trimmed {
+		switch i {
+		case 8, 13, 18, 23:
+			if r != '-' {
+				return false
+			}
+		default:
+			if !isHexDigit(r) {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+func isHexDigit(r rune) bool {
+	return (r >= '0' && r <= '9') || (r >= 'a' && r <= 'f') || (r >= 'A' && r <= 'F')
+}