feat(auth): Add security questions for account recovery

## Description Allow users to set up security questions and answers as an alternative account recovery method. Store answers securely using hashing to prevent exposure in case of database breach. ## Acceptance Criteria - [ ] Create predefined list of security questions - [ ] Allow users to select and answer 3 security questions - [ ] Hash answers before storing (similar to passwords) - [ ] Add recovery flow using security questions ## Files to Modify - Update `src/models/User.ts` (add securityQuestions field) - Create `src/routes/auth/security-questions.ts` - Update `src/routes/auth/recover.ts` - Add frontend security questions setup