fix: Backend platform-aware Agent-Update (nicht mehr hardcoded freebsd)

backend/api/firmware.go

@@ -184,8 +184,20 @@ func (h *Handler) pushAgentUpdate(hub *ws.Hub) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		agentID := r.PathValue("id")
 
-		// TODO: Agent-Plattform aus DB lesen; fuer jetzt default freebsd
-		version, hash, binary, err := h.db.GetLatestFirmware("freebsd")
+		// Plattform aus Request-Body oder Query-Parameter lesen, default linux
+		platform := r.URL.Query().Get("platform")
+		if platform == "" {
+			var reqBody struct {
+				Platform string `json:"platform"`
+			}
+			body, _ := io.ReadAll(r.Body)
+			json.Unmarshal(body, &reqBody)
+			platform = reqBody.Platform
+		}
+		if platform == "" {
+			platform = "linux"
+		}
+		version, hash, binary, err := h.db.GetLatestFirmware(platform)
 		if err != nil {
 			writeError(w, http.StatusNotFound, "Keine Firmware verfuegbar")
 			return