Make sync status non-blocking

internal/db/connection.go

@@ -238,6 +238,22 @@ func (cm *ConnectionManager) Disconnect() {
 	cm.lastError = nil
 }
 
+// MarkOffline closes the current connection and preserves the last observed error.
+func (cm *ConnectionManager) MarkOffline(err error) {
+	cm.mu.Lock()
+	defer cm.mu.Unlock()
+
+	if cm.db != nil {
+		sqlDB, dbErr := cm.db.DB()
+		if dbErr == nil {
+			sqlDB.Close()
+		}
+	}
+	cm.db = nil
+	cm.lastError = err
+	cm.lastCheck = time.Now()
+}
+
 // GetLastError returns the last connection error (thread-safe)
 func (cm *ConnectionManager) GetLastError() error {
 	cm.mu.RLock()