fix(madimack_elitev4): handle current temperature of 0 as null

If current temperature is reported as 0, redirect to the alternative
inflow sensor as it is likely a missing or broken sensor.

Issue #3412

custom_components/tuya_local/devices/madimack_elitev4_heatpump.yaml

@@ -60,6 +60,8 @@ entities:
         mapping:
           - dps_val: null
             value_redirect: inflow_temperature
+          - dps_val: 0
+            value_redirect: inflow_temperature
       - id: 110
         type: integer
         name: max_temperature

custom_components/tuya_local/manifest.json

@@ -18,5 +18,5 @@
         "tinytuya==1.17.4",
         "tuya-device-sharing-sdk~=0.2.1"
     ],
-    "version": "2025.9.0"
+    "version": "2025.9.1"
 }