Add back 'Off' Preset Mode, remove DP1 'off' constraint and set an initial default DP1 value before Preset contraints are evaluated

custom_components/tuya_local/devices/cecotec_readywarm_8400.yaml

@@ -13,10 +13,9 @@ primary_entity:
         - dps_val: false
           value: "off"
         - dps_val: true
+          value: fan_only
           constraint: preset_mode
           conditions:
-            - dps_val: "null"
-              value: fan_only
             - dps_val: "low"
               value: heat
               hidden: true
@@ -39,6 +38,9 @@ primary_entity:
       name: preset_mode
       type: string
       mapping:
+        - dps_val: "off"
+          value: none
+          hidden: true
         - dps_val: "low"
           value: eco
         - dps_val: "high"