Clean up dead code after Angular brand story removal

- Delete HomeCtrl controller file (nothing references it anymore)
- Remove misplaced .text-vbig class from <details> (was on the old <a> toggle; summary has no visible text)
- Remove redundant cursor: pointer on #brand-story-text (<summary> already sets it)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/assets/javascripts/darkswarm/controllers/home_controller.js.coffee

@@ -1,2 +0,0 @@
-angular.module('Darkswarm').controller "HomeCtrl", ($scope) ->
-  # Controller kept for potential future use

app/views/home/_brandstory.html.haml

@@ -6,7 +6,7 @@
       %p
         = t :brandstory_intro
 
-      %details#brand-story-text.text-vbig
+      %details#brand-story-text
         %summary
           %i.ofn-i_005-caret-down
           %i.ofn-i_006-caret-up

app/webpacker/css/darkswarm/home_panes.scss

@@ -72,7 +72,6 @@
   }
 
   #brand-story-text {
-    cursor: pointer;
     text-align: center;
     margin-top: 1rem;