feat(controller): add source for command handling.

feat(telegram): switch message type to markdown
feat(controller): add welcome message for telegram bot.

internal/controller/pipes/qq_napcat/qq.go

@@ -179,12 +179,12 @@ func (q *QQController) processCommand(cmd controller.Command) string {
 	parsed.ChatID = cmd.ChatID
 	parsed.ChatType = cmd.ChatType
 	parsed.SenderID = cmd.SenderID
+	parsed.Source = "qq_napcat"
 
 	// Hand the complete command to the unified processor, which checks group
 	// vs private, trusted groups, admin permissions, and executes it.
 	response, err := controller.GetManager().Trigger(parsed, q.cfg.TrustedGroups, q.cfg.Admins, q.cfg.ListenMethod)
-	cfg := config.GetConfig()
-	if cfg.System.DebugMode && cfg.Debug.ShowTriggerCmdEcho {
+	if config.GetConfig().System.DebugMode && config.GetConfig().Debug.ShowTriggerCmdEcho {
 		postLog.Debug(fmt.Sprintf("[qq_napcat] triggered command: \"/%s\" with args: \"%s\" from chatID: %d and senderID: %d", parsed.Command, strings.Join(parsed.Args, ", "), cmd.ChatID, cmd.SenderID))
 	}
 	if err != nil {