Add Default Pomodoro Presets (25/5 & 50/10)

[AkshayAshokCode]

🎯 Objective

Introduce commonly used default Pomodoro session presets that users can choose from quickly, without having to manually configure each time value.

📦 Details

Add the following two preset configurations:

1. 🍅 Classic Pomodoro (25/5)
   Session Duration: 25 minutes
   Short Break: 5 minutes
   Long Break: 15 minutes
   Long Break After: 4 sessions
2. ⚡ Deep Work Mode (50/10)
   Session Duration: 50 minutes
   Short Break: 10 minutes
   Long Break: 30 minutes
   Long Break After: 2 sessions