Data Privacy and Security

### Brief description
As a _User_
I need _my personal data and habit information to be protected_
So that _I can feel confident that my information is private and secure_


### Details and Assumptions
* Data encryption will be used for sensitive user information.
* The app must comply with GDPR, CCPA, or other relevant data privacy laws.
* Users will have control over what data is collected and how it’s used.
* Two-factor authentication (2FA) will be supported for enhanced security

### Acceptance Criteria

```gherkin
Given I have an account
When I use the app
Then my personal and habit data should be encrypted and stored securely
```

```gherkin
Given I am concerned about privacy
When I review the privacy policy
Then I should be able to see what data is collected and how it is used
```

```gherkin
Given I want additional security
When I enable 2FA
Then I should receive a second authentication prompt (e.g., SMS or email) upon login
```