Fix Beacon admin sidebar links — use paths without site prefix

Beacon admin pages (/beacon/*) were generating sidebar links with
the site prefix (e.g., /admin/dockyard_com/beacon/users) because
maybe_link always called beacon_live_admin_path with the site.

Now build_link_path/3 detects /beacon/* paths and generates links
without the site prefix (e.g., /admin/beacon/users).

Added beacon_live_admin_path/2 (socket, path) for generating
platform-level paths without a site segment.

Author: bcardarella

lib/beacon/live_admin/live/page_live.ex

@@ -311,7 +311,7 @@ defmodule Beacon.LiveAdmin.PageLive do
   end
 
   defp maybe_link(socket, page, {:current, text, icon, path}) do
-    path = Beacon.LiveAdmin.Router.beacon_live_admin_path(socket, page.site, path)
+    path = build_link_path(socket, page, path)
     assigns = %{text: text, icon: icon, path: path}
 
     # use href to force redirecting to re-execute plug to fecth current url
@@ -329,7 +329,7 @@ defmodule Beacon.LiveAdmin.PageLive do
   end
 
   defp maybe_link(socket, page, {:enabled, text, icon, path}) do
-    path = Beacon.LiveAdmin.Router.beacon_live_admin_path(socket, page.site, path)
+    path = build_link_path(socket, page, path)
     assigns = %{text: text, icon: icon, path: path}
 
     # force redirect to re-execute plug to fecth current url
@@ -355,4 +355,14 @@ defmodule Beacon.LiveAdmin.PageLive do
     </span>
     """
   end
+
+  # Beacon admin pages (/beacon/*) don't need the site prefix
+  defp build_link_path(socket, _page, "/beacon" <> _ = path) do
+    Beacon.LiveAdmin.Router.beacon_live_admin_path(socket, path)
+  end
+
+  # Site-scoped pages get the site prefix
+  defp build_link_path(socket, page, path) do
+    Beacon.LiveAdmin.Router.beacon_live_admin_path(socket, page.site, path)
+  end
 end

lib/beacon/live_admin/router.ex

@@ -398,6 +398,23 @@ defmodule Beacon.LiveAdmin.Router do
     Phoenix.VerifiedRoutes.unverified_path(conn_or_socket, router, path, %{})
   end
 
+  @doc """
+  Generates a path without a site prefix (for platform-level pages).
+
+  ## Example
+
+      iex> Beacon.LiveAdmin.Router.beacon_live_admin_path(@socket, "/beacon/users")
+      "/my_admin/beacon/users"
+
+  """
+  @spec beacon_live_admin_path(conn_or_socket, String.t()) :: String.t()
+  def beacon_live_admin_path(conn_or_socket, path) when is_binary(path) do
+    router = router(conn_or_socket)
+    prefix = router.__beacon_live_admin_prefix__()
+    path = sanitize_path("#{prefix}#{path}")
+    Phoenix.VerifiedRoutes.unverified_path(conn_or_socket, router, path, %{})
+  end
+
   @doc """
   Generate the path to serve files in `priv/static`.