refactor(ui): update staff identity label to "官方"

Change staff identity display text from "职工认证" to "官方" and update
corresponding colors to gold theme in UserProfileHeader and
VerificationSettingsScreen.

src/components/business/UserProfileHeader.tsx

@@ -586,7 +586,7 @@ const IDENTITY_CONFIG: Record<
   general: { label: '未认证', color: '#9CA3AF', bg: '#F3F4F6' },
   student: { label: '学生认证', color: '#10B981', bg: '#D1FAE5' },
   teacher: { label: '教师认证', color: '#3B82F6', bg: '#DBEAFE' },
-  staff: { label: '职工认证', color: '#8B5CF6', bg: '#EDE9FE' },
+  staff: { label: '官方', color: '#D4AF37', bg: '#FFF8DC' },
   alumni: { label: '校友认证', color: '#F59E0B', bg: '#FEF3C7' },
   external: { label: '未认证', color: '#9CA3AF', bg: '#F3F4F6' },
 };

src/screens/profile/VerificationSettingsScreen.tsx

@@ -57,7 +57,7 @@ const IDENTITY_TEXT: Record<string, string> = {
   general: '普通用户',
   student: '在校学生',
   teacher: '教职工',
-  staff: '工作人员',
+  staff: '官方工作人员',
   alumni: '校友',
   external: '外部人员',
 };