feat(android): add attachment boxing FJ- scan and submit

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

lib/pages/boxing/parts/boxing_submit_part.dart

@@ -6,6 +6,53 @@ extension _BoxingSubmitPart on _BoxingPageState {
   Future<bool> _submit() async {
     if (!_canSubmit) return false;
 
+    final attachCatId = _attachmentCategoryId;
+    if (attachCatId != null) {
+      // Attachment boxing submit
+      setState(() => _isSubmitting = true);
+      final action = await _apiActions.saveAttachmentBox(
+        zongpaiNo: _zongpaiNo!,
+        categoryId: attachCatId,
+        boxNo: int.parse(_boxNoController.text),
+        quantity: int.parse(_quantityController.text),
+      );
+      if (!mounted) return false;
+      setState(() => _isSubmitting = false);
+
+      if (action.success) {
+        _feedbackService.trigger(FeedbackEvent.submitSuccess);
+        // Reset to waiting for next scan
+        setState(() {
+          _zongpaiNo = null;
+          _phase = BoxingPhase.waiting;
+          _attachmentCategoryId = null;
+          _attachmentCategoryName = null;
+        });
+        _showStatusOverride(
+          '附件装箱成功',
+          StatusDotColor.green,
+          const Duration(milliseconds: 1500),
+        );
+        _requestFocus();
+        return true;
+      } else if (action.errorKind == BoxingActionErrorKind.duplicate) {
+        _feedbackService.trigger(FeedbackEvent.duplicateBoxNo);
+        _showStatusOverride(
+          action.errorMessage ?? '该箱号已存在同类型附件',
+          StatusDotColor.red,
+          const Duration(seconds: 2),
+        );
+      } else {
+        _feedbackService.trigger(FeedbackEvent.submitFailure);
+        _showStatusOverride(
+          action.errorMessage ?? '提交失败',
+          StatusDotColor.red,
+          const Duration(seconds: 2),
+        );
+      }
+      return false;
+    }
+
     final boxNo = int.parse(_boxNoController.text);
     final quantity = int.parse(_quantityController.text);