Initial backend and database setup

Changes Made

• Created Flask application setup (app.py)
• Added project configuration (config.py)
• Created database connection file (database/db.py)
• Added database schema (database/schema.sql)
• Created email utility (utils/email_service.py)
• Added project dependencies (requirements.txt)
• Added technical documentation (TECHNICAL_DOCUMENTATION.md)

Testing

• Flask application runs successfully on localhost:5000
• Initial project structure verified
• Files pushed successfully to remote repository

Purpose

This merge request adds the initial backend and database setup for the Water Leakage Reporting Portal project.