feat: shadcn -> rust-ui.com migration + TorrentDetail silme

- Tüm leptos-shadcn-* paketleri kaldırıldı (19 dependency)
- leptos_ui, tw_merge, strum eklendi
- components/ui/ modülü oluşturuldu (Button, Card, Input)
- TorrentDetail bileşeni tamamen silindi
- sidebar.rs: saf HTML+Tailwind ile SidebarButton yardımcı bileşeni
- toolbar.rs, login.rs, setup.rs, add_torrent.rs: saf HTML+Tailwind
- table.rs: shadcn Card -> rust-ui Card
- app.rs: Skeleton -> animate-pulse div

frontend/src/components/torrent/table.rs

@@ -4,7 +4,7 @@ use crate::store::{get_action_messages, show_toast};
 use crate::api;
 use shared::NotificationLevel;
 use crate::components::context_menu::TorrentContextMenu;
-use leptos_shadcn_card::{Card, CardHeader, CardTitle, CardContent};
+use crate::components::ui::card::{Card, CardHeader, CardTitle, CardContent};
 
 fn format_bytes(bytes: i64) -> String {
     const UNITS: [&str; 6] = ["B", "KB", "MB", "GB", "TB", "PB"];