Feature: AI Smart Alarm - Sleep Better & Wake Up Fresh

### Description

## Overview
Add simple sleep tracking to help users sleep better and wake up refreshed.

## Features
1. **Track Sleep Time**
- Show total hours slept
- Display bedtime and wake time
- Weekly sleep history view

2. **Smart Alarm**
- Wakes you up at the best time
- Set your wake-up window (±30 min)
- Gentle wake-up sounds

3. **Motivation**
- Simple sleep streaks
- Weekly sleep goals
- Encouraging notifications

## Why?
- Users want to improve their sleep
- Helps build better sleep habits
- Makes waking up easier
- Simple and easy to understand

## Technical Notes
- Uses phone sensors for sleep detection
- Integrates with existing alarm system
- Clean, dark UI with green accents
- Flutter implementation

## Success Metrics
- User sleep duration
- Morning alarm ratings
- App retention rates

### Screenshots


This is the UI design