feat: pomodoro timer added

[inderjeet20]

Description

This PR adds a complete pomodoro timer functionality to the app, allowing users to:

1. Configure work intervals (1-120 minutes)
2. Set break durations (1-30 minutes)
3. Choose the number of intervals (1-10)
4. Categorize sessions with custom labels
5. Notification support when intervals complete

Fixes #760

Screenshots

https://github.com/user-attachments/assets/e48db354-a7c4-41b4-80e2-1fe3495eae7e

What's Next

Add session history and statistics

Testing

Tested on multiple screen sizes Verified that timer settings persist correctly Confirmed that custom labels are saved properly

[Gaurav-Kushwaha-1225]

Hi @inderjsingh, Don't you think the UI is very inconsistent? Please try to use similar theme colors and widget designs.