feat: add right sidebar with table of contents, scroll spy, and reading progress tracking

frontend/index.html

@@ -337,6 +337,34 @@
         </div>
       </main>
 
+      <!-- Right sidebar resize handle -->
+      <div class="right-sidebar-resize-handle" id="right-sidebar-resize-handle"></div>
+
+      <!-- Right Sidebar (Outline/TOC) -->
+      <aside class="right-sidebar" id="right-sidebar" role="complementary" aria-label="Table des matières">
+        <div class="right-sidebar-header">
+          <h2 class="right-sidebar-title">SUR CETTE PAGE</h2>
+          <button class="right-sidebar-toggle-btn" id="right-sidebar-toggle-btn" type="button" title="Masquer le panneau" aria-label="Masquer le panneau">
+            <i data-lucide="chevron-right" style="width:16px;height:16px"></i>
+          </button>
+        </div>
+        <div class="outline-panel" id="outline-panel">
+          <nav class="outline-list" id="outline-list" role="navigation" aria-label="Navigation dans le document">
+            <!-- Outline items will be injected here -->
+          </nav>
+          <div class="outline-empty" id="outline-empty" hidden>
+            <i data-lucide="list" style="width:24px;height:24px;opacity:0.3"></i>
+            <span>Aucun titre dans ce document</span>
+          </div>
+        </div>
+        <div class="reading-progress" id="reading-progress">
+          <div class="reading-progress-bar">
+            <div class="reading-progress-fill" id="reading-progress-fill"></div>
+          </div>
+          <div class="reading-progress-text" id="reading-progress-text">0%</div>
+        </div>
+      </aside>
+
     </div>
   </div>