feat: add graph navigation links in menu and planner

- Add "Grafo de Dependencias" to the drawer menu (first 9 semesters)
- Add graph icon link in the planner header

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

Author: RenzoMinelli

app/views/shared/_menu.html.erb

@@ -5,6 +5,8 @@
 
   <%= drawer_menu_navigation_item "Todas las Materias", all_subjects_path %>
 
+  <%= drawer_menu_navigation_item "Grafo de Dependencias", subjects_graph_path(categories: Subject::CATEGORIES.first(9)) %>
+
   <%= drawer_menu_navigation_item "Materias dictadas en este semestre", current_semester_subjects_path %>
 
   <%= drawer_menu_navigation_item "Planificador", subject_plans_path %>

app/views/subject_plans/index.html.erb

@@ -1,6 +1,6 @@
 <% content_for :welcome_banner do %>
-  <%= render 'shared/banner', 
-      banner_type: 'planner', 
+  <%= render 'shared/banner',
+      banner_type: 'planner',
       message: 'Bienvenido a tu planificador de materias: arrastra, suelta y organiza tu semestre' %>
 <% end %>
 
@@ -10,9 +10,14 @@
 
 <div id="planner" class="relative pt-3 space-y-4" data-controller="planner-loading">
   <div class="flex items-center justify-between h-10 mb-3">
-    <h3 class="text-lg font-bold ml-4">
-      Planificador
-    </h3>
+    <div class="flex items-center gap-2 ml-4">
+      <h3 class="text-lg font-bold">
+        Planificador
+      </h3>
+      <%= link_to planner_graph_path, class: "text-gray-500 hover:text-primary", title: "Ver grafo de dependencias" do %>
+        <%= material_icon("account_tree", class: "text-xl") %>
+      <% end %>
+    </div>
     <%= render partial: "credits_counter", locals: { planned_subjects: @planned_subjects } %>
   </div>