feat: link transit registration to boxing

lib/services/registration_linking.dart

@@ -0,0 +1,39 @@
+import 'package:flutter/material.dart';
+import 'package:pad_scanner/services/code_parser.dart';
+
+const batchPaichaMismatchMessage = '批量凑箱仅支持同排产号产品，请移除不属于同一批次的总排号';
+
+bool isTransitTarget(CodeType? locationType, String? locationCode) {
+  return locationType == CodeType.locationTransit ||
+      (locationCode?.startsWith('TRANS-') ?? false);
+}
+
+String registrationSubmitLabel({
+  required bool isTransitTarget,
+  required bool isLocked,
+  required int zongpaiCount,
+}) {
+  if (!isTransitTarget) {
+    return isLocked && zongpaiCount > 1 ? '批量上架（$zongpaiCount 条）' : '确 认 上 架';
+  }
+  return isLocked && zongpaiCount > 1 ? '批量转运并凑箱（$zongpaiCount 条）' : '转运并装箱';
+}
+
+Color registrationSubmitColor({
+  required bool canSubmit,
+  required bool isTransitTarget,
+  required Color primaryColor,
+}) {
+  if (!canSubmit) return Colors.grey.shade300;
+  return isTransitTarget ? Colors.orange : primaryColor;
+}
+
+bool allSamePaicha(Iterable<String?> paichaNos) {
+  String? first;
+  for (final paichaNo in paichaNos) {
+    if (paichaNo == null || paichaNo.isEmpty) return false;
+    first ??= paichaNo;
+    if (paichaNo != first) return false;
+  }
+  return first != null;
+}