fix: restore dnd on focus pause

[alv-cor]

This pull request primarily focuses on correctly restoring Do Not Disturb (DND) mode and refining the Pomodoro phase transition logic. The changes ensure DND is restored at appropriate times and that Pomodoro transitions are handled more clearly and efficiently.

Focus mode and Pomodoro logic improvements:

• Restores DND mode immediately when focus mode ends by calling restoreDND() at the end of a session.
• Refactors Pomodoro phase transition logic to only call transitionPomodoroPhase() if the session is in Pomodoro mode, improving clarity and correctness.

Notification and feedback handling:

• Ensures DND is restored at the start of a Pomodoro break phase regardless of auto-start settings, and refactors the order and conditions for playing transition sounds and vibrations for better reliability.

[PranavPurwar]

i think we should only toggle the setting when the option is enabled.

[alv-cor]

i think we should only toggle the setting when the option is enabled.

Thanks for your answer!

According to the app settings, if the toggle is enabled it will Silence notifications during focus, but this is not implemented right currently since breaks in pomodoro or manual pauses in plain focus session are not focus time by meaning, and DND keeps on.