HEL-203: 修复原因弹窗作用域、首屏断档与表单 reset

将 openModal/closeModal 提升为顶层唯一定义，公司端启动即加载断档提醒，
并在 await 前提取表单引用；补充 Playwright 两端冒烟与源码契约测试。

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: multica-agent <github@multica.ai>

tests/test_company_transfers_page.py

@@ -32,7 +32,7 @@ class TransfersPageSourceContractTests(unittest.TestCase):
         self.assertIn("期间净变动", html)
         self.assertNotIn("本公司往来合计", html)
         self.assertIn("design-system.css?v=6", html)
-        self.assertIn("app.js?v=12", html)
+        self.assertIn("app.js?v=13", html)
         # 侧栏顺序：流水管理 → 转账往来 → 往来确认
         flows = html.index('data-view="flows"')
         transfers = html.index('data-view="transfers"')
@@ -113,7 +113,7 @@ class TransfersPageLayoutSmokeTests(unittest.TestCase):
             for width in (360, 820, 1440):
                 page.set_viewport_size({"width": width, "height": 900})
                 page.set_content(
-                    html.replace('src="app.js?v=12"', 'src=""'),
+                    html.replace('src="app.js?v=13"', 'src=""'),
                     base_url=self.base,
                 )
                 page.evaluate(