Add SQLite Database

[AugustAtSeattle]

Implement SQLite database for data persistence.

Tasks:

• [x] 3.1. Define Database Schema.
• [x] 3.2. Implement Database Access Layer.
• [x] 3.3. Integrate SQLite with App.
• [x] 3.4. Test Database Functionality.

Ensure CRUD operations and data retrieval are functioning properly.