feat: Optimize UI layout with fixed navigation and scrollable content

Layout Optimization:
- Fixed navigation bar at the top with sticky positioning
- Main content area now properly scrollable with flex layout
- Improved overall page structure for better UX

 Scrolling Enhancements:
- Added custom scrollbar styling for better visual appeal
- Implemented smooth scrolling behavior across the application
- Optimized scroll areas in ProjectDetails, TemplateManagement, AiClassificationSettings, and ModelList
- Added proper overflow handling for long content lists

 Visual Improvements:
- Beautiful custom scrollbars with hover effects
- Proper height constraints for content areas (calc(100vh-16rem))
- Enhanced scrolling experience with backdrop blur effects
- Added scroll indicators and shadow effects for better UX

 Responsive Design:
- Mobile-optimized scrolling behavior
- Proper touch scrolling on mobile devices
- Adaptive content heights for different screen sizes
- Maintained accessibility with reduced motion support

 Technical Improvements:
- Fixed JSX syntax errors in TemplateManagement and ModelList
- Improved component structure for better maintainability
- Added comprehensive CSS classes for scroll management
- Enhanced performance with optimized overflow handling

All pages now provide a smooth, professional scrolling experience while keeping the navigation always accessible.

apps/desktop/src/pages/AiClassificationSettings.tsx

@@ -336,8 +336,8 @@ const AiClassificationSettings: React.FC = () => {
               </h2>
             </div>
 
-            {/* 美观的分类卡片网格 */}
-            <div className="grid gap-4">
+            {/* 美观的分类卡片网格 - 优化滚动 */}
+            <div className="grid gap-4 max-h-[calc(100vh-16rem)] overflow-y-auto custom-scrollbar">
               {classifications.map((classification, index) => (
                 <div
                   key={classification.id}