refactor: overhaul NFO settings UI and backend

- Rework nfo-settings page with improved styling and layout
- Update edit-modal and context-menu with enhanced functionality
- Refactor NFO API endpoints and models
- Remove deprecated test_nfo_diagnostics_repair.py
- Clean up tasks.md documentation

src/server/web/static/js/index/context-menu.js

@@ -71,6 +71,10 @@ AniWorld.ContextMenu = (function() {
                 <i class="fa-solid fa-pen-to-square"></i>
                 <span>Edit Metadata</span>
             </div>
+            <div class="context-menu-item" data-action="nfo-diagnostics">
+                <i class="fa-solid fa-file-circle-check"></i>
+                <span>NFO Diagnostics</span>
+            </div>
         `;
 
         document.body.appendChild(menuElement);
@@ -102,6 +106,13 @@ AniWorld.ContextMenu = (function() {
                 AniWorld.EditModal.open(currentSeriesKey);
             }
         });
+
+        // NFO Diagnostics - opens the full NFO settings page
+        menuElement.querySelector('[data-action="nfo-diagnostics"]').addEventListener('click', function() {
+            hide();
+            // Navigate to NFO settings page with this series selected
+            window.location.href = '/settings/nfo?key=' + encodeURIComponent(currentSeriesKey);
+        });
     }
 
     /**