refactor: sidebar layout for Tech Support and Feature Manager

- Add <aside class="sidebar"> with #sidebar-support and #sidebar-features to index.html
- Restyle .main-content as flex layout (sidebar left, tiles right)
- Body is now display:flex column with overflow:hidden for independent scroll panels
- Sidebar (270px fixed) with overflow-y:auto scrolls independently
- Tiles area (flex:1) scrolls independently
- New sidebar support button (.sidebar-support-btn) replaces support tile in main grid
- Feature Manager now renders into #sidebar-features instead of $tilesArea
- Compact sidebar overrides for .feature-card padding/font-size
- Remove 'support' and 'feature-manager' from CATEGORY_ORDER
- Responsive: sidebar becomes full-width above tiles at <=768px

Agent-Logs-Url: https://github.com/naturallaw777/staging_alpha/sessions/4304350a-bc4f-4698-82b5-8ee28f0ad960

Co-authored-by: naturallaw777 <99053422+naturallaw777@users.noreply.github.com>

app/sovran_systemsos_web/templates/index.html

@@ -34,6 +34,10 @@
 
   <!-- Service tiles -->
   <main class="main-content">
+    <aside class="sidebar" id="sidebar">
+      <div id="sidebar-support"></div>
+      <div id="sidebar-features"></div>
+    </aside>
     <div id="tiles-area"></div>
   </main>