Fix access check form: use GET so results render

The access check form POSTed and re-rendered :new with a 200 HTML
response, which Turbo rejects ("Form responses must redirect to
another location"), so the result panel never appeared. Since the
check is a read-only query, switch to a GET form and fold the lookup
into the new action. Results are now bookmarkable via the URL.

Bump version to 0.16.2.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/controllers/admin/access_checks_controller.rb

@@ -2,17 +2,12 @@ module Admin
   class AccessChecksController < BaseController
     def new
       load_options
-    end
-
-    def create
-      load_options
       @user = User.find_by(id: params[:user_id])
       @application = Application.find_by(id: params[:application_id])
-      return render :new unless @user && @application
+      return unless @user && @application
 
       @allowed = @application.user_allowed?(@user)
       @via = @user.groups & @application.allowed_groups
-      render :new
     end
 
     private