feat: add dashboard route, template, and styles for project and scenario insights

templates/partials/base_header.html

@@ -1,10 +1,10 @@
 <div class="sidebar-inner">
-  <div class="sidebar-brand">
+  <a class="sidebar-brand" href="{{ request.url_for('dashboard.home') }}">
     <span class="brand-logo" aria-hidden="true">CM</span>
     <div class="brand-text">
       <span class="brand-title">CalMiner</span>
       <span class="brand-subtitle">Mining Planner</span>
     </div>
-  </div>
+  </a>
   {% include "partials/sidebar_nav.html" %}
 </div>