feat: add show_in_legal to admin content page editor

- Add "Show in Legal" checkbox to content page editor UI
- Update API schemas (ContentPageCreate, ContentPageUpdate, ContentPageResponse)
- Add show_in_legal parameter to service methods (create_page, update_page, etc.)
- Fix ContentPageNotFoundException to pass identifier correctly
- Fix UnauthorizedContentPageAccessException to use correct AuthorizationException API
- Add comprehensive unit tests for ContentPageService (35 tests)
- Add content page fixtures for testing
- Update CMS documentation with navigation categories diagram

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/templates/admin/content-page-edit.html

@@ -189,7 +189,7 @@
                 Navigation & Display
             </h3>
 
-            <div class="grid grid-cols-1 md:grid-cols-3 gap-4">
+            <div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-4">
                 <!-- Display Order -->
                 <div>
                     <label class="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
@@ -226,6 +226,21 @@
                         </span>
                     </label>
                 </div>
+
+                <!-- Show in Legal (Bottom Bar) -->
+                <div class="flex items-center">
+                    <label class="flex items-center cursor-pointer">
+                        <input
+                            type="checkbox"
+                            x-model="form.show_in_legal"
+                            class="w-5 h-5 text-purple-600 border-gray-300 rounded focus:ring-purple-500"
+                        >
+                        <span class="ml-3 text-sm font-medium text-gray-900 dark:text-white">
+                            Show in Legal
+                        </span>
+                    </label>
+                    <span class="ml-2 text-xs text-gray-500 dark:text-gray-400" title="Bottom bar next to copyright">(?)</span>
+                </div>
             </div>
         </div>