[Bug Report & Feature Request] Pomodoro

I've been using pomodoro timer a lot recently for work and productivity, and I have a couple of requests.

1. The timer doesn't really seem to follow the pomodoro technique, just sets of 25 minutes and 5 minutes. Pomodoro is supposed to be every 4 sessions, there's supposed to be a longer rest period of 15-30 minutes.

2. When I set a timer with the default clock app on my phone, I can close the clock app and still look at the notifications to see how long is left in the timer. Since LockIn already has access to notifications, I'd like to see if a similar idea is possible.

https://github.com/user-attachments/assets/f2b0d98d-fda4-4c64-9fa3-4e15aaeea97d

The issue names no files or tests. Start by locating the Pomodoro timer flow and notification handling in the Flutter app; check how sessions are counted and what platform notification support exists. Done means a longer break follows each four sessions and an active timer exposes its remaining time through notifications, with checks covering both requests.

Written by the indexing model from the issue text.