fix: Echo user requested setpoint for kelvin

If the bulb's color temperature changes because of an ST-initiated user
requested setpoint, we emit that directly instead of clamping to the
step size. This is to remain consistent with the way things are done on
the rest of the platform with other integrations.

drivers/SmartThings/philips-hue/src/fields.lua

@@ -33,6 +33,7 @@ local Fields = {
   COLOR_SATURATION = "color_saturation",
   COLOR_HUE = "color_hue",
   SWITCH_STATE = "switch_state_cache",
+  COLOR_TEMP_SETPOINT = "ct_setpoint"
 }
 
 return Fields

drivers/SmartThings/philips-hue/src/handlers/attribute_emitters.lua

@@ -101,8 +101,17 @@ local function _emit_light_events_inner(light_device, light_repr)
           )
         )
       else
+        local last_kelvin_setpoint = light_device:get_field(Fields.COLOR_TEMP_SETPOINT)
+        if
+          last_kelvin_setpoint ~= nil and
+          last_kelvin_setpoint >= utils.mirek_to_kelvin(mirek + 1) and
+          last_kelvin_setpoint <= utils.mirek_to_kelvin(mirek - 1)
+        then
+          kelvin = last_kelvin_setpoint;
+        end
         light_device:emit_event(capabilities.colorTemperature.colorTemperature(kelvin))
       end
+      light_device:set_field(Fields.COLOR_TEMP_SETPOINT, nil);
     end
 
     if light_repr.color then

drivers/SmartThings/philips-hue/src/handlers/commands.lua

@@ -249,6 +249,7 @@ local function do_color_temp_action(driver, device, args)
       end
     end
   end
+  device:set_field(Fields.COLOR_TEMP_SETPOINT, clamped_kelvin);
 end
 
 ---@param driver HueDriver