feat(mobile-h5): add mock auth helpers for login page

Co-authored-by: Cursor <cursoragent@cursor.com>

mobile-h5/utils/validate-credentials.js

@@ -0,0 +1,7 @@
+export function validateCredentials(username, password) {
+  const u = (username || '').trim()
+  const p = password || ''
+  if (!u) return { ok: false, code: 'EMPTY_USERNAME', message: '请输入用户名 / 工号' }
+  if (!p) return { ok: false, code: 'EMPTY_PASSWORD', message: '请输入密码' }
+  return { ok: true }
+}