CSS: remove remaining fixable inline styles across templates

- Suppress modal form groups: strip margin-bottom:12px (lt-form-group
  already has margin-bottom in TDS); use lt-form-group--last for the
  final group where zero margin is needed
- Keyboard shortcuts table: remove width:100% (lt-table is already full-
  width in base.css)
- Settings divider: replace style=margin override with .lt-divider--compact
- Topology bus section: move max-width:860px into .topo-bus-section rule

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

templates/index.html

@@ -253,7 +253,7 @@
          TIER 4 connecting bus – two rails (10G green + 1G amber dashed)
          showing dual-homing for all 6 servers
          ══════════════════════════════════════════════════════════ -->
-    <div class="topo-bus-section" style="max-width:860px;">
+    <div class="topo-bus-section">
 
       <!-- 10G storage bus (Agg → VLAN90) -->
       <div class="topo-bus-10g">