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/database/core/DatabaseConfig.ts

@@ -9,6 +9,6 @@ export const DB_CONFIG = {
   DB_NAME_PREFIX: 'carrot_bbs_',
 } as const;
 
-export const getDbName = (userId: string | null): string => {
+export function getDbName(userId: string | null): string {
   return userId ? `${DB_CONFIG.DB_NAME_PREFIX}${userId}.db` : DB_CONFIG.DEFAULT_DB_NAME;
-};
+}