Fix used_input? implementation and update test

- Replace incorrect pc_used_input? implementation with Phoenix.Component.used_input?
- Update dual range slider error test to include field in params
- All tests now passing

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: nhobes

lib/petal_components/field.ex

@@ -122,7 +122,7 @@ defmodule PetalComponents.Field do
 
   # When a FormField struct is provided, normalize and delegate rendering.
   def field(%{field: %Phoenix.HTML.FormField{} = field} = assigns) do
-    errors = if pc_used_input?(field), do: field.errors, else: []
+    errors = if used_input?(field), do: field.errors, else: []
 
     assigns
     |> assign(field: nil, id: assigns.id || field.id)
@@ -978,8 +978,4 @@ defmodule PetalComponents.Field do
     end
   end
 
-  # Renamed helper to avoid conflict with Phoenix.Component.used_input?/1
-  defp pc_used_input?(field) do
-    field.errors != []
-  end
 end

test/petal/field_test.exs

@@ -950,7 +950,7 @@ defmodule PetalComponents.FieldTest do
         field: :price_range,
         id: "price_range",
         form: %Phoenix.HTML.Form{
-          params: %{},
+          params: %{"price_range" => nil},
           source: %{},
           impl: Phoenix.HTML.FormData.Ecto.Changeset,
           name: "filter"