fix(client): 统一打印错误处理，失败时上报并弹提示

新增 safePrint 封装，所有打印调用点统一 catch 任意异常（含字体加载失败），
自动上报 error_reporter 并展示 SnackBar，不再静默失败。

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/lib/screens/stock_out/stock_out_form_screen.dart

@@ -222,7 +222,7 @@ class _StockOutFormScreenState extends ConsumerState<StockOutFormScreen> {
 
   Future<void> _printOrder() async {
     if (_loadedOrder == null) return;
-    await printStockOutOrder(_loadedOrder!);
+    await safePrint(context, () => printStockOutOrder(_loadedOrder!));
   }
 
   Future<void> _submit(bool asDraft) async {

client/lib/screens/stock_out/stock_out_list_screen.dart

@@ -1,5 +1,7 @@
 import '../../repositories/product_repository.dart';
 import '../../core/utils/dialog_util.dart';
+import '../../core/errors/error_reporter.dart';
+import '../../core/utils/print_util.dart' show safePrint, printStockOutOrder, printProductLabel;
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:go_router/go_router.dart';
@@ -254,15 +256,9 @@ class _StockOutListScreenState extends ConsumerState<StockOutListScreen> {
               ),
               TextButton(
                 onPressed: () async {
-                  try {
-                    final order = await ref.read(stockOutRepositoryProvider).get(o.id);
-                    await printStockOutOrder(order);
-                  } catch (e) {
-                    if (context.mounted) {
-                      ScaffoldMessenger.of(context).showSnackBar(
-                        SnackBar(content: Text(e.toString()), backgroundColor: Colors.red),
-                      );
-                    }
+                  final order = await ref.read(stockOutRepositoryProvider).get(o.id);
+                  if (context.mounted) {
+                    await safePrint(context, () => printStockOutOrder(order));
                   }
                 },
                 child: const Text('打印',
@@ -690,17 +686,7 @@ class _StockOutDetailDialogState extends ConsumerState<_StockOutDetailDialog> {
                     IconButton(
                       icon: const Icon(Icons.print_outlined, color: Colors.white),
                       tooltip: '打印',
-                      onPressed: () async {
-                        try {
-                          await printStockOutOrder(_loadedOrder!);
-                        } catch (e) {
-                          if (context.mounted) {
-                            ScaffoldMessenger.of(context).showSnackBar(
-                              SnackBar(content: Text(e.toString()), backgroundColor: Colors.red),
-                            );
-                          }
-                        }
-                      },
+                      onPressed: () => safePrint(context, () => printStockOutOrder(_loadedOrder!)),
                     ),
                   IconButton(
                     icon: const Icon(Icons.close, color: Colors.white),
@@ -960,10 +946,9 @@ class _LabelPrintDialogState extends State<_LabelPrintDialog> {
         );
         done++;
         if (mounted) setState(() => _status = '已打印 $done 张...');
-      } catch (e) {
-        if (mounted) {
-          setState(() => _status = '第${i + 1}行打印失败：$e');
-        }
+      } catch (e, st) {
+        reportError(e, st);
+        if (mounted) setState(() => _status = '第${i + 1}行打印失败：$e');
       }
     }
     if (mounted) {