feat(web): add chevron affordance and scope-badge slot to dropdown triggers

Dropdown openers were visually indistinguishable from ordinary buttons. A
trailing chevron now marks every dropdown trigger — both the shared
dropdown_menu component and the bespoke member-filter trigger — and an
optional badge slot lets a trigger show a status indicator beside its label.

lib/mv_web/components/core_components.ex

@@ -464,6 +464,9 @@ defmodule MvWeb.CoreComponents do
 
   slot :inner_block, doc: "Custom content for the dropdown menu (e.g., forms)"
 
+  slot :trigger_badge,
+    doc: "Optional badge rendered in the trigger after the label (e.g. a scope badge)"
+
   def dropdown_menu(assigns) do
     menu_testid = assigns.menu_testid || "#{assigns.testid}-menu"
 
@@ -498,6 +501,8 @@ defmodule MvWeb.CoreComponents do
           <.icon name={@icon} />
         <% end %>
         <span>{@button_label}</span>
+        {render_slot(@trigger_badge)}
+        <.icon name="hero-chevron-down" class="size-4" />
       </button>
 
       <ul

lib/mv_web/live/components/member_filter_component.ex

@@ -156,6 +156,7 @@ defmodule MvWeb.Components.MemberFilterComponent do
         >
           {@member_count}
         </.badge>
+        <.icon name="hero-chevron-down" class="size-4" />
       </.button>
       
     <!--

test/mv_web/components/field_visibility_dropdown_component_test.exs

@@ -17,5 +17,13 @@ defmodule MvWeb.Components.FieldVisibilityDropdownComponentTest do
       assert has_element?(view, "button[phx-click='select_all']")
       assert has_element?(view, "button[phx-click='select_none']")
     end
+
+    test "trigger carries a trailing chevron affordance", %{conn: conn} do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, ~p"/members")
+
+      # The shared dropdown trigger signals "opens a menu" with a trailing chevron.
+      assert html =~ "hero-chevron-down"
+    end
   end
 end

test/mv_web/components/member_filter_component_test.exs

@@ -49,6 +49,20 @@ defmodule MvWeb.Components.MemberFilterComponentTest do
   end
 
   describe "rendering" do
+    test "trigger carries a trailing chevron affordance", %{conn: conn} do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members")
+
+      # Mirror the shared dropdown affordance: a trailing chevron inside the
+      # bespoke filter trigger button.
+      chevron =
+        html
+        |> LazyHTML.from_fragment()
+        |> LazyHTML.query(~s(#member-filter button[aria-haspopup="true"] .hero-chevron-down))
+
+      assert Enum.count(chevron) == 1
+    end
+
     test "renders boolean custom fields when present", %{conn: conn} do
       conn = conn_with_oidc_user(conn)
       boolean_field = create_boolean_custom_field(%{name: "Active Member"})

test/mv_web/components/sort_header_component_test.exs

@@ -82,8 +82,10 @@ defmodule MvWeb.Components.SortHeaderComponentTest do
       conn = conn_with_oidc_user(conn)
       {:ok, _view, html} = live(conn, "/members?query=&sort_field=email&sort_order=desc")
 
-      # Count occurrences to ensure only one descending icon
+      # Count occurrences to ensure only one descending sort icon. Dropdown
-      down_count = html |> String.split("hero-chevron-down ") |> length() |> Kernel.-(1)
+      # triggers carry their own trailing "hero-chevron-down size-4" chevron, so
+      # the sort-active icon is identified by its bare class (no size-4 suffix).
+      down_count = active_sort_down_count(html)
       # Should be exactly one chevrondown icon
       assert down_count == 1
     end
@@ -158,7 +160,7 @@ defmodule MvWeb.Components.SortHeaderComponentTest do
 
       # Count active icons (should be exactly 1 - ascending for default sort field)
       up_count = html_neutral |> String.split("hero-chevron-up ") |> length() |> Kernel.-(1)
-      down_count = html_neutral |> String.split("hero-chevron-down ") |> length() |> Kernel.-(1)
+      down_count = active_sort_down_count(html_neutral)
 
       assert up_count == 1, "Expected exactly 1 ascending icon, got #{up_count}"
       assert down_count == 0, "Expected 0 descending icons, got #{down_count}"
@@ -167,13 +169,24 @@ defmodule MvWeb.Components.SortHeaderComponentTest do
       {:ok, _view, html_desc} = live(conn, "/members?sort_field=first_name&sort_order=desc")
 
       up_count = html_desc |> String.split("hero-chevron-up ") |> length() |> Kernel.-(1)
-      down_count = html_desc |> String.split("hero-chevron-down ") |> length() |> Kernel.-(1)
+      down_count = active_sort_down_count(html_desc)
 
       assert up_count == 0, "Expected 0 ascending icons, got #{up_count}"
       assert down_count == 1, "Expected exactly 1 descending icon, got #{down_count}"
     end
   end
 
+  # Counts only the descending chevron icons that belong to a sort header. Both
+  # the sort-active icon and the dropdown-trigger chevron render as
+  # "hero-chevron-down size-4", so they are told apart by their containing
+  # button: sort headers carry phx-click="sort", dropdown triggers do not.
+  defp active_sort_down_count(html) do
+    html
+    |> LazyHTML.from_fragment()
+    |> LazyHTML.query(~s(button[phx-click="sort"] .hero-chevron-down))
+    |> Enum.count()
+  end
+
   describe "accessibility" do
     test "sets aria-label correctly for unsorted state", %{conn: conn} do
       conn = conn_with_oidc_user(conn)