Attempt fix to ignore constant null action traffic for H2 EU dimmer

aqara-h2-eu-dimmer-z2m-light-control.yaml

@@ -111,6 +111,14 @@ max: 15
 trigger:
   - platform: mqtt
     topic: !input mqtt_topic
+    payload: "action"
+    value_template: >
+      {{ 'action'
+         if value_json is defined
+         and value_json.action is defined
+         and value_json.action is not none
+         and (value_json.action | string | length > 0)
+         else 'ignore' }}
 
 action:
   - variables:
@@ -121,6 +129,8 @@ action:
       # Time since the previous MQTT event triggered this automation.
       # Genuine stop_rotating events immediately follow rotation events.
       # The H2 bug emits a stray stop_rotating after the device has been idle.
+      # Null/missing action packets are filtered at the MQTT trigger above,
+      # so only genuine action events affect this timer.
       idle_seconds: >
         {{ as_timestamp(now()) -
            as_timestamp(