fix: canonicalize phone numbers as E.164

server/validate/tel/validate_test.go

@@ -0,0 +1,13 @@
+package tel
+
+import "testing"
+
+func TestPreCheckDefaultsToChina(t *testing.T) {
+	got, err := (&validator{}).PreCheck("13800138000", map[string]any{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != "tel:+8613800138000" {
+		t.Fatalf("got %q, want tel:+8613800138000", got)
+	}
+}