Data Backup and Synchronization

### Brief description
As a _User_
I need _my habit data to be securely stored and synchronized_
So that _I can access my progress across multiple devices_


### Details and Assumptions
* Data will be stored in a secure cloud database.
* Changes in habit data (e.g., progress, streaks) will be synced across all devices in real-time.
* Users will always have the latest version of their data, even if switching between devices.

### Acceptance Criteria

```gherkin
Given I have multiple devices
When I log in on a new device
Then all my habit data should be synchronized and up-to-date
```

```gherkin
Given I make changes to my habits on one device
When I switch to another device
Then the updated data should be reflected instantly
```