feat: implement asynchronous timer start

- add new StartAsync method to Timer for non-blocking execution
- use new method in RunPomodoro()

🤖

internal/pomodoro/pomodoro.go

@@ -42,7 +42,7 @@ func RunPomodoro() {
 
 		// Work
 		shared.State.Mode = "Work"
-		go timer.Start(pomodoroConfig.Work)
+		timer.StartAsync(pomodoroConfig.Work)
 		if !waitForTimer(timer) {
 			break
 		}
@@ -50,13 +50,13 @@ func RunPomodoro() {
 		// Breaks
 		if session < pomodoroConfig.Sessions {
 			shared.State.Mode = "ShortBreak"
-			go timer.Start(pomodoroConfig.ShortBreak)
+			timer.StartAsync(pomodoroConfig.ShortBreak)
 			if !waitForTimer(timer) {
 				break
 			}
 		} else { // last phase, prepare for finish
 			shared.State.Mode = "LongBreak"
-			go timer.Start(pomodoroConfig.LongBreak)
+			timer.StartAsync(pomodoroConfig.LongBreak)
 			if !waitForTimer(timer) {
 				break
 			}