施工(HEL-226): 实现登录门户与本机免密切换账号

用设备 Cookie 和授权表记住本机已验证账号，登录页按确认样图做成门户，不再把密码写进浏览器。

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

tests/test_governance_registries.py

@@ -65,8 +65,11 @@ class GovernanceRegistryTests(unittest.TestCase):
             public,
             {
                 ("GET", "/api/health"),
+                ("GET", "/api/auth/accounts"),
                 ("POST", "/api/auth/login"),
                 ("POST", "/api/auth/register"),
+                ("POST", "/api/auth/switch"),
+                ("POST", "/api/auth/forget"),
             },
         )