[hue] Improve support for third party lights

bundles/org.openhab.binding.hue/src/main/java/org/openhab/binding/hue/internal/api/dto/clip2/Dimming.java

@@ -30,7 +30,7 @@ public class Dimming {
     private @Nullable Double brightness;
     private @Nullable @SerializedName("min_dim_level") Double minimumDimmingLevel;
 
-    public static final double DEFAULT_MINIMUM_DIMMIMG_LEVEL = 0.5f;
+    public static final double DEFAULT_MINIMUM_DIMMIMG_LEVEL = 0.39f;
 
     /**
      * @throws DTOPresentButEmptyException to indicate that the DTO is present but empty.

bundles/org.openhab.binding.hue/src/main/java/org/openhab/binding/hue/internal/handler/Clip2ThingHandler.java

@@ -438,6 +438,7 @@ public void handleCommand(ChannelUID channelUID, Command commandParam) {
                     putResource = Setters.setDimming(putResource, brightnessCommand, cache);
                     Double minDimLevel = Objects.nonNull(cache) ? cache.getMinimumDimmingLevel() : null;
                     minDimLevel = Objects.nonNull(minDimLevel) ? minDimLevel : Dimming.DEFAULT_MINIMUM_DIMMIMG_LEVEL;
+                    minDimLevel = minDimLevel == 0.0 ? 0.01 : minDimLevel; // exact 0.0 must cause OFF (e.g. 'Signe')
                     command = OnOffType.from(brightnessCommand.doubleValue() >= minDimLevel);
                 }
                 // NB fall through for handling of switch related commands !!