feat: implement permanent broadcast message functionality

- add SendPermanentBroadCastMessage to continuously send updates
- refactor BroadcastMessage to use a shared Message struct
- update pomodoro logic to modify broadcast.Message directly
- adjust client command handling to use broadcast.Clients map
- enhance ServerMessage struct with "Ongoing" and "Paused" fields

🤖

pkg/models/server.go

@@ -6,4 +6,6 @@ type ServerMessage struct {
 	Session      int    `json:"session"`        // Current session number
 	TotalSession int    `json:"total_sessions"` // Total number of sessions
 	TimeLeft     int    `json:"time_left"`      // Remaining time in seconds
+	Ongoing      bool   `json:"ongoing"`        // Ongoing pomodoro
+	Paused       bool   `json:"paused"`         // Is timer paused
 }