fix(meshcore): move UI into visuals container, fix layout

meshcoreMode partial was inside the generic .sidebar which gets hidden
when meshcore mode is active. Moved the include into meshcoreVisuals
(inside the output panel) — matching the same pattern as Meshtastic.
Also overrides mesh-visuals-container's column/padding defaults so the
meshcore sidebar+main row layout renders correctly.

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

static/css/modes/meshcore.css

@@ -1,14 +1,19 @@
 /* Meshcore mode — scoped styles */
 
-#meshcoreMode {
-    display: none;
+/* Override the shared mesh-visuals-container column layout */
+#meshcoreVisuals {
     flex-direction: row;
-    height: 100%;
+    padding: 0;
     gap: 0;
 }
 
-#meshcoreMode.active {
-    display: flex !important;
+#meshcoreMode {
+    display: flex;
+    flex-direction: row;
+    flex: 1;
+    min-height: 0;
+    overflow: hidden;
+    gap: 0;
 }
 
 /* ── Sidebar ── */

templates/index.html

@@ -779,7 +779,6 @@
                 {% include 'partials/modes/spy-stations.html' %}
 
                 {% include 'partials/modes/meshtastic.html' %}
-                {% include 'partials/modes/meshcore.html' %}
 
                 {% include 'partials/modes/websdr.html' %}
 
@@ -2366,6 +2365,7 @@
 
                 <!-- Meshcore Dashboard -->
                 <div id="meshcoreVisuals" class="mesh-visuals-container" style="display: none;">
+                    {% include 'partials/modes/meshcore.html' %}
                 </div>
 
                 <!-- SSTV Decoder Dashboard -->

templates/partials/modes/meshcore.html

@@ -1,5 +1,5 @@
 {# Meshcore Mode Partial #}
-<div id="meshcoreMode" class="mode-content" style="display:none; flex-direction: row; height: 100%;">
+<div id="meshcoreMode" style="display:flex; flex-direction: row; flex: 1; min-height: 0; overflow: hidden;">
 
   {# ── Sidebar ── #}
   <div class="meshcore-sidebar">