refactor: update UI components and styles for improved consistency and functionality

- Refactored Skeleton component to include data-slot attribute and updated class names.
- Enhanced Switch component with size prop and improved styling.
- Updated Tooltip components to include data-slot attributes and improved styling.
- Refactored global CSS to use custom properties for theming and improved dark mode support.
- Added useIsMobile hook for responsive design handling.
- Updated IPC link implementation for tRPC in Electron.
- Adjusted ProjectsPage layout for better responsiveness.
- Removed outdated Tailwind configuration file and integrated Tailwind CSS with Vite.

src/renderer/components/layout/AppShell.tsx

@@ -57,7 +57,7 @@ export function AppShell({ children }: AppShellProps) {
   return (
     <SidebarProvider open={open} onOpenChange={handleOpenChange}>
       <AppSidebar currentPath={currentPath} />
-      <SidebarInset className="overflow-hidden">
+      <SidebarInset>
         {children}
 
         {/* Right-edge vertical 'keep scrolling for AI' affordance (non-interactive) */}