feat(auth): add user identity verification system with new screens

Add comprehensive identity verification flow including:
- New verification guide screen at /verification-guide for selecting identity type
- New verification form screen at /verification-form for submitting verification documents
- Verification settings screen at /profile/verification for managing verification status
- Move terms and privacy policy to root-level routes (/terms, /privacy)
- Update login to require active terms agreement checkbox
- Database: add in-memory fallback when OPFS is unavailable on web

BREAKING CHANGE: Terms and privacy policy routes moved from /profile/terms and /profile/privacy to /terms and /privacy

src/screens/profile/index.ts

@@ -17,6 +17,7 @@ export { AccountSecurityScreen } from './AccountSecurityScreen';
 export { AboutScreen } from './AboutScreen';
 export { TermsOfServiceScreen } from './TermsOfServiceScreen';
 export { PrivacyPolicyScreen } from './PrivacyPolicyScreen';
+export { VerificationSettingsScreen } from './VerificationSettingsScreen';
 
 // 导出 Hook 供需要自定义的场景使用
 export { useUserProfile, createSharedProfileStyles, TABS, TAB_ICONS } from './useUserProfile';