Enhance App UI with logo and animations

- Added a voicebox logo to the loading screen in the App component for improved branding.
- Introduced fade-in animations for the logo and loading text to enhance user experience.
- Updated Sidebar component styles for better visual consistency.
- Refactored HistoryTable to implement a new fixed-height row layout, improving readability and interaction.
- Removed unused Badge component from GenerationForm for cleaner code.

app/src/components/Sidebar.tsx

@@ -37,8 +37,8 @@ export function Sidebar({ activeTab, onTabChange }: SidebarProps) {
               onClick={() => onTabChange(tab.id)}
               className={cn(
                 'w-12 h-12 rounded-full flex items-center justify-center transition-all duration-200',
-                'hover:bg-accent hover:text-accent-foreground',
-                isActive ? 'bg-accent text-accent-foreground shadow-lg' : 'text-muted-foreground',
+                'hover:bg-muted/50',
+                isActive ? 'bg-muted/50 text-foreground shadow-lg' : 'text-muted-foreground',
               )}
               title={tab.label}
               aria-label={tab.label}